that would be rather hard to implement imo, since OMPT would have to guess what is the "default" setting for each parameter on each VST(i) wich is impossible.
Setting everything to 0 won't solve much, because we used to have pannings example that should stay on center (CC 64?) or wet/dry that are usually on 100%.
Manually setting everything to stance that is the most confortable for you to start building your effect or sound, and saving that setting to a "mysynth_blank.fxb" example will do the job very nice.
In the end, some "experimental- set everything to 0" option could be useful maybe in some cases, but i would rather vote for manually setting once up, and saving that to "blank".