Squash blossoms over long weekend

Big flowers are almost bigger than pot

This is the second sign of actual food production so far. The first was a gathering of barely visible tomato blossoms on the Roma hanging upside down on the patio.

These two showed up curled and looking like any of the leaf buds but then turned into a flower about midway through the day. By this morning (5/29) they had curled up and were looking pretty dang sad. This might have a lot to do with the fact that these very large plants are still living in peat seed starter pots about as big around as one of their leaves.

Which brings up a critical question: I had read that one should never transplant anything in bloom. Is that correct? What transplant guidelines apply to vegetables vs flowering plants?