Justafewdahlias Overall, no - if I’ve accidentally cut an overripe bloom then some bruising can occur and I’ll toss it, but more for being overripe.
I’m pretty rough with the blooms though and haven’t noticed damage. I dunk the blooms up and down aggressively and swirl and twist to release the pockets of air first (little critters can hole-up and wait out the bath!). I did have the stem of one snap in this process the other day, but Temps at night have cooled down quite a bit and stems are beginning to lose their muster.
Truthfully, most blooms look more refreshed and even more hydrated afterward (fluffier petals with more substance!). I like this process for that alone.