NM, I used two decider combinators and a constant combinator to enable the belt for a certain number of ticks. Thanks anyway!

Perhaps an entity (e.g. Belt Buffer 0.17) that I could change output speed?

I want to make a mod that allows belts to be slowed much like inserts can override stack size. So far as I can tell, belt speed can only be changed during startup. Am I missing something that would allow this?