So with this mod using Quality parts in Rocket Silo, has no effect,
Other than allowing you to use up the higher quality ingredients.
(Allowing you to use them normally instead of trashing them cause you have to many.)

Thanks

Yup.
Sadly I couldn't work out how to make quality do anything.

I've fixed it!
Quality rocket parts now build the rocket faster.

In my opinion there is a better way to do it other than giving the bonus with an on_nth_tick script that has to fire frequently to be accurate, you could define some hidden rocket silos with adjusted rocket_parts_required parameter:
https://lua-api.factorio.com/latest/prototypes/RocketSiloPrototype.html#rocket_parts_required
and with a script swap the regular user placed silos with the hidden ones accordingly. You would still have to have an on_nth_tick handler to check for silos that might've gotten their recipes changed, but it could reasonably be done much less frequently and probably for cheaper.