As far as I'm aware, if an Accelerator is used on your server, it will also accelerate the parsing of your templates, as you said, it's just php code.
Encoders however, just encode the scripts, sometimes they speed up bottlenecks, however they do not offer considerable performance increases. And how would you "support" them anyway?
vLIB is open source. If you wish to improve it, go ahead.. any changes will be gratefully reviewed.
Kelvin