I haven't noticed this issue so can't really help, sorry. I assume you are using a recent NVIDIA driver and the latest build of rF2? You could try the Bits setting 0x02502005 which is also supposed to work, but I think it is very similar to 0x00500005 so you might have the same problems with flickering. Also you could try increasing or decreasing the in-game Environment Reflection settings in case one of them works without any flickering (just as a test). ISI have been updating reflections a lot in recent builds so there might be some bugs you are experiencing.