I measured my feet again. If i push it to the wall (not with force) and push the ruler to it, then i can measure 10.5 inches too. My measures are 10.5" (little pushed) to 10.7" but in 42 spyridons, my big toe reached the end of the toe pockets in the store. I didn't tried 41 but I also tried 43 treksports and they had a little bit larger toe pockets for me.
Should I go 42 in seeyas and 41 in treks? Or 41 both? or 42? are these both able to stretch with some time and break in 0.2 inches? I don't need socks

I can't try these on here and I dont think i can send back if i chose wrong:/
Monkeyshoes: do you have seeyas? If yes, what size? How does it fit? What is your shoe length?
I think you should check the fit with both, 41 and 42, and no, I do not have the seeyas but want them, the seeya ls.