You are right about putting them on before you have any leg pump. I have pretty skinny legs and wear extra smalls. They go on pretty well but getting them off after sweating and leg pump can be challenging particularly since that they are long.
I generally fold mine in half top to bottom and put them on like that.
I’ve had mine a couple of years and haven’t noticed much break in but then I also use a couple of different pairs of Titan sleeves as well and mostly keep the SPDs for competition and leading up to competition.