I actually did a run of removing parts while on the tripod. Easier to work on but definitely some parts can fall further and easier. Fortunately this did not happen to me but I could see it happen if I was not careful. I did find that adjusting the worm drive was better while on the mount as I could adjust while connected and was able to fine tune with much greater accuracy.
I was pleasantly surprised how easy it was too, found 4 gritty bearings and replace them, the cone bearing were fine and I need to make a puller to remove the other ones. They seemed OK though very smooth and are sealed bearings too.
Reminded me of the days I was re-building motorbike engines