Huh.
So if the patch is about .75" it would be about 1/112 of the wheel circumference and about 1/4 of the tube circumference.
The thickness of a patch is similar to the difference in thickness between a standard tube, and a lighter tube.
The difference in rolling resistance between those tubes is about 1 watt for pair of tires at 45kph,
so a patch could theoretically require about .0022 watts at 45kph.
https://www.aero-coach.co.uk/inner-t...ing-resistance
Then, if I have the math right, they suggest a 4 second difference in a 40k TT for 1 watt of RR,
so a tube patch could cost you .0088 of a second over a 40k time trial at 45kph.