If you simply have a version of your scenery for Honolulu PHNL where because you have already purchased a copy, all the elements are there(no need for couatl.exe) and there is no need to edit performance parameters using Addon Manager (bglmanx.dll), it would be usable.
You are falling into the trap of assuming that, the only thing that our modules do, is to handle the protection/activation, and to tweak FSX parameters. That's not the case (we tried to explain it many times, yet people fail to understand, since the activation/tweak part is the only part *they* get in touch with, so they assume it's the only thing the module do).
The integration is far deeped than it seems: the sceneries are made in a way that it's simply impossible to have them without the Addon Manager/Couatl modules, and it's not possible to go back (we need to use the modules ourselves even during developement), because they use functions exposed by the modules, and rely on them to be created on the fly.
So no, there's no chance to use any our products in a sim that doesn't have a version of the module specifically made for it so, to support ESP we would need Addon Manager/Couatl for ESP and to support Prepar3D, we would need them for Prepar3D.
With regard to the decision to support ESP or Prepar3D, it's really a more practical than a technical one: we never had used ESP ourselves, and it would be silly for us to buy a license for it, now that Prepar3D is available.
We also think that everyone that bought ESP, would eventually migrate to Prepar3D, since no commercial environment would be confortable using an unsupported product which has no future roadmap and surely not a chance for upgrades, fixes, etc.
