There's are reasons not to update to P3D 4.5 from 4.3, surely not for performance reasons, if a system could run 4.3, it will surely run 4.5 too.
We updated most of the models in GSX to support PBR, which works with 4.4 minium, but not only that, we are also using several features which are just not there in previous versions, like the custom Camera API, which allows us to create native cameras with *zero* impact on fps and no hacking, or more reliable Render To Texture features, which allowed to reduce dramatically the number of Simobject installed, for a performance INCREASE, and a way easier user customization of operator liveries.
That's why we cannot support 4.3 and below, SAME AS:
- we don't support any version lower than 3.4 on P3D V3 ( and nobody ever complained )
- we don't support any version lower than 2.5 on P3D V2 ( and nobody ever complained )
- we don't support any other version than 1.4 on P3D V1 ( and nobody ever complained )
- we don't support FSX without BOTH Service Packs 1 and 2 installed ( and nobody ever complained )