Yeah, I’m thinking it must just be that when they start to deaden into their sound they seem a little more loose, the sound less crisp and tight. Somehow I think this affects how I perceive the playability of the string. I seem to remember the same happening to rounds back when I actually played rounds.I don't find they change tension wise at all.
I don’t know, I’ve tried too many flats in the past few years on all my basses, I think I’m starting to go nuts...