As explained so many times already, this scenery was made as full-PBR scenery right from the start so, we cannot offer a non-PBR like other developers that already had one, since their PBR version was an update of a non-PBR version they already had.
What you call shimmering ( the proper name is moire effect ) is a byproduct of using normal maps, which are mandatory for PBR to work. It can be seen on each and every PBR product out there, just search around and you'll find plenty of discussions about that related to PBR aircraft.
The amount of the effect changes depending on the time of the day, the viewing angle, the screen resolution and the video settings. To reduce it, be sure you have these settings:
- Anisotropic Filtering at 16x
- One of the SSAA Antialiasing modes enabled. It's much worse with MSAA or with no Antialiasing
