I have the same issue. In my sim I chose to use '2x Sparse Grid Supersampling' (a mix of MSAA and SSAA), when using MSAA it is *killing* performance at night with dynamic lighting.
Are you sure you are referring to MSAA to killing peformances at night ? MSAA is what you shouldn't use, because it causes shimmering but, it's usually a bit better for fps.
In any case, there's no point discussing this anymore. With no tweaks, SSAA WILL look like in the screenshot at Page 6 of the manual, and that's how the scenery is supposed to look like.
For those that tweaked their system and for any reasons ( compatibility, personal tastes, performances ), so they are unable/unwilling to set the proper antialiasing mode as suggested in the manual, we'll shortly release an alternate set of textures with toned down textures, like we did with KORD V2. It will look more flat, even at day when the problem doesn't exists, but it will surely reduce shimmering at night.
No, we won't make it to switch automatically from PBR to PBR-less from day to night, even if we could, because dynamic texture switching has some performance cost associated with it, since a LUA script should be used for these textures, and scripts are evaluated at each frame, for each material that has one, so we want to use them only if strictly necessary.
So, with the next Live Update, you'll find an alternate set of ground textures which will be more flat, but they will have to be enabled manually.
