That is not even remotely correct. A lot of native game-functions are not useable from MTA's provided funtion-set. Also, I'm pretty sure he was speaking of applying client-mods like the widescreen patch. Even if you could recreate it with MTA's functions (granted, it's mostly possible), the server would have to have it installed as a resource.
Seeing as certain versions of ENB are allowed, I think this should be added. Perhaps allow admins to whitelist certain .ASI mods by using a list of md5-keys. The client can enable/disable the initialization of .ASI mods in the settings (disabled by default). Perhaps this could also allow for an easy way to at least lift some of the limits?
EDIT: Then again, those md5s can be manipulated by the client, so it might not be a good idea after all.