Yes, memorably. A partner once abandoned me when I was approaching climax, leaving me desperate to finish myself off...but my one free hand felt hopelessly inadequate to stimulate enough of my penis. "It's got too...much...surface..." I panted, desperately wishing my penis was short enough to fit comfortably in that one free hand. Even at that moment, I was amazed to realize I was yearning for my penis to be smaller...and I fantasized wildly about it. What if it was so small I could squeeze the whole thing in my fist...so small that I could wrap my fingers around it entirely...
Since then I've frequently fantasized about scaling down my dick (or someone else's) on the premise that it all those sensations could be concentrated into a conveniently more-compact size. Super concentrated. High efficiency. Double strength.
I used to think I was 9 inches, until my GF measured me and said "you're only 8 inches!"
Heh, that reminds me of a reverse experience. I had told someone my penis was "less than 9 inches," but they later exclaimed, "Are you sure it's
only nine inches?" (Apparently its slenderness exaggerates its length.)