A small section of 3/4" isn't going to have much effect.
With city water, the setters are 5/8" or 3/4", and we run 1" or 1-1/4" off of those.
A long distance of 3/4" would have been more of a worry, the distance adding to the friction loss.
If you look at a hosebib, the port that the water comes through is very small. And yet it will gush out of there.