Q.how do you cultivate shallot top sets?
Due to unusual spring weather this year my shallots sprouted top sets. They have affected the development of the bulb dramatically. I have never seen this happen before. Their appearance has affected the development of the bulb. Should I break off the scape when the set appears? Should I let them develop and possibly plant them? Are they edible? Do they make viable sets for next season planting?
It is likely due to due to cold or other stress. Being biannual, a cold spell fools the bulb into thinking it's been winter and then, when the weather turns warm, they produce a flower. You can try removing the flower and then as the stem dries, lift these bulbs; though small, they are certainly edible.
Replanting these is not likely viable.