The conundrum is when your business' reputation is established on original/custom design work, especially creating higher price points. Transferring credibility to other designers is vital for a 'design oriented' florist to grow.
A florist whose niche is production work or by-the-numbers arrangements has little need for direct consumer-designer contact except for perhaps family sympathy work and weddings.
We have tags that provide the identity of our designers on custom work. I just wrote about good news for one of them in a blog post this week.
Has promoting designers' identities ever bit me? Uh-huh - but I find the reward for the business (through growth) and staff morale to be far, far greater than the risk, so far.