I started leaving the throttle springs connected on all of my engines about 2 years ago. Partly because I was too lazy to disconnect them (It does take about 2 seconds after all) but mainly because it gives me a shutoff when I make a mistake and have a linkage disconnect (which ironically hasn't happened to me on an engine that has the spring connected). I don't know the exact load figure but I do know it has made absolutley no difference to the number of flights I get in per flight pack charge.

Actually, thinking about this since reading the OP. This method could be an interesting way around some of the side carb engines that are difficult to align a throttle rod to a servo. Maybe some fishing rollers with a cable to change the direction of the pull pull

Go on captin - you know you want to experiment more - this is a hobby after all