A florist friend not on this forum always allows two stalks per tuber, saying he grows for quantity and not size. He also shows, but flowers are his livelihood.

We can't overwinter in my zone, but here are my thoughts...
The problem you might run into is that each tuber in a clump will want its own sprout/s and if you don't dig/divide/replant, it might be a downhill battle to limit growth... They might keep on sending sprouts out until you're tired of fighting them and they sneak past you anyways.

Last year, as an experiment, I let several shoots grow on a few of my tubers, instead of paring them down to one.

My observation was that the main stalks were weaker, (not the flower stems). It was much more difficult to keep them staked, since there was more to stake and they needed more support. I did get more flowers though.

Thanks for the suggestions. I think I'll leave multiple stems (two or three) and see how this bed compares to the single tuber single stem plants in the rest of the beds.