[Snowshoe]

Sun - I see no reason why this is disabled, or why the sun corona would be a problem.

Motion Blur - Some people like this, others don't. Personally it bothers me, but I don't see how it affects a multiplayer game. I guess this was turned off because it bothered racers?

Grass - Grass done properly can work without needing to sync the solid objects (like rocks). The grass and bush models are non-solid so they don't need to be synced. You can simply remove the other solid plants by editing data/procobj.dat and storing that inside samp.saa. Example here. This example file allows only non-solid stuff to generate.

[MP2]

I believe the sun is tied to motion blur and the grass, but I could be wrong, or there could be a way around it.

Procedural objects (e.g. grass) was enabled in one version of SA-MP. 0.2.2 R3 IIRC. It caused crashes and lag spikes, so was removed (IIRC).

It's easily possible to enable these things with mods, so it's not like they're forbidden - just disabled.

[Arastair]

hmm... never realized that motion blur was disabled, I don't see any reason to disable it unless it causes crash or something like MP2 Mentioned

[NaS]

Grass is disabled due to different settings in the clients. Some cannot see (for example) through the whole area 51 because of vegetation while others, with low settings, can see everything. Performance was not the reason I guess.

Motion blur affects the performance and thus looks laggy for others if it's not synced in any way (or fixed).

[niCe]

Procedural objects are disabled, because it could cause desync, as these objects also include for example some randomly placed rocks on Mount Chiliad, so while one player would be standing on that rock, other players would see them floating in the air, there would also be desynchronized collisions and much more.

Motion blur, as far as I know, was disabled as it's not synced either and doesn't look well from passengers seat.