Found a way to set the flag. Log below: the PMDG737Variant() line keeps repeating until the end of the log file (when I hit the Quit to Desktop button). As the log was 680MB at this point, the zip file was too large to upload.
[00:00:00.031] Running in mode: Microsoft Flight Simulator 2024
[00:00:00.047] Python 3.7.9 Stackless 3.7 (tags/v3.7.9-slp-dirty:8ad319a856, May 22 2021, 22:48:12) [MSC v.1916 64 bit (AMD64)]
[00:00:00.047] wxPython 4.2.0
[00:00:00.047] Couatl v5.0 (build 6213)
[00:00:00.047] log started on Mon Dec 22 18:02:03 2025
[00:00:00.047]
[00:00:00.047] connecting to SimConnect...
[00:00:00.172] connected to bglmanx
[00:00:00.187] RunningMode::pathToInstalledPackages D:\MSFS Content\MSFS2024 Content
[00:00:00.187] Loading addons
[00:00:00.187] Loading addon common
[00:00:00.281] Addon common loaded
[00:00:00.281] Loading addon LiveUpdate
[00:00:00.281] Addon LiveUpdate loaded
[00:00:00.281] requesting AddOn list to bglmanx
[00:00:46.344] Simulator version: 12.2.282174.999
[00:00:50.015] bglmanx list contains 33 AddOn(s)
[00:00:50.015] Loading addon LFSB
[00:00:50.172] Addon LFSB loaded
[00:00:50.172] Loading addon GSX
[00:00:50.219] Current sim directory is D:/MSFS Addons/Addon Manager/couatl64
[00:00:50.859] Addon GSX loaded
[00:00:50.859] Loading addon GSX.airports.kiah_fsdt_MSFS
[00:00:50.875] Addon GSX.airports.kiah_fsdt_MSFS loaded
[00:00:50.875] Loading addon KIAH2
[00:00:50.875] Addon KIAH2 loaded
[00:00:50.875] Loading addon GSX.airports.kord_v2_fsdt_MSFS
[00:00:50.890] Addon GSX.airports.kord_v2_fsdt_MSFS loaded
[00:00:50.890] Loading addon GSX.airports.ksdf_fsdt_MSFS
[00:00:50.890] Addon GSX.airports.ksdf_fsdt_MSFS loaded
[00:00:50.890] Loading addon GSX.airports.lszh_fsdt_MSFS
[00:00:50.906] Addon GSX.airports.lszh_fsdt_MSFS loaded
[00:00:50.906] Loading addon GSX.airports.cyvr_fsdt_MSFS
[00:00:50.906] Addon GSX.airports.cyvr_fsdt_MSFS loaded
[00:00:50.906] Loading addon GSX.airports.keyw_fsdt_MSFS
[00:00:50.906] Addon GSX.airports.keyw_fsdt_MSFS loaded
[00:00:50.906] Loading addon GSX.airports.kclt_fsdt_MSFS
[00:00:50.922] Addon GSX.airports.kclt_fsdt_MSFS loaded
[00:00:50.922] Loading addon GSX.airports.lfeq_fsdt_MSFS
[00:00:50.922] Addon GSX.airports.lfeq_fsdt_MSFS loaded
[00:00:50.922] Starting system monitors
[00:00:50.922] [KIAH2] is active
[00:00:56.156] Slew mode False
[00:00:59.109] USER airplane title reported by Simconnect is 737-800 BBJ2 SSW
[00:00:59.125] Livery Name is "PMDG HOUSE BBJ2 (N738BA | 2025)"
[00:00:59.125] Livery Folder is "PMDG HOUSE BBJ2 SSW"
[00:00:59.125] Loading aircraft.cfg from d:\msfs content\msfs2024 content\community\pmdg-aircraft-738\simobjects\airplanes\pmdg 737-800\presets\pmdg\pmdg 737-bbj2 ssw\config
[00:00:59.125] Loading engines.cfg from d:\msfs content\msfs2024 content\community\pmdg-aircraft-738\simobjects\airplanes\pmdg 737-800\presets\pmdg\pmdg 737-bbj2 ssw\config
[00:00:59.125] Loading flight_model.cfg from d:\msfs content\msfs2024 content\community\pmdg-aircraft-738\simobjects\airplanes\pmdg 737-800\presets\pmdg\pmdg 737-bbj2 ssw\config
[00:00:59.125] Loading gameplay.cfg from d:\msfs content\msfs2024 content\community\pmdg-aircraft-738\simobjects\airplanes\pmdg 737-800\presets\pmdg\pmdg 737-bbj2 ssw\config
[00:00:59.125] Loading systems.cfg from d:\msfs content\msfs2024 content\community\pmdg-aircraft-738\simobjects\airplanes\pmdg 737-800\presets\pmdg\pmdg 737-bbj2 ssw\config
[00:00:59.140] ATC_ID read from aircraft.cfg is N738BA
[00:00:59.140] this airplane has 0 exits
[00:00:59.140] MSFS 2024 Airplane detected as pmdg 737-800
[00:00:59.140] Model: "ATCCOM.AC_MODEL B738.0.text" (length: 27)
[00:00:59.140] Title: "737-800 BBJ2 SSW" (length: 16)
[00:00:59.140] Airplane major/minor version 737/800
[00:00:59.156] ATC_ID_SIM read from Simconnect is D-MCPR
[00:00:59.156] Searching airplane
[00:00:59.156] Searching airplane PMDG 737-800
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"
[00:00:59.156] PMDG737Variant() baseName = "PMDG 737-800" title = "737-800 bbj2 ssw" variant = "800-BBJ2" profile = "PMDG 737-800BBJ2"