I spent most of my gardening life cutting off the flowering scapes of hardneck garlic so they wouldn't draw energy from the bulbs. Then I read a story about a garlic growing guru who said it didn't matter a whit.
Well, it isn't really much bother. Tender young scapes are delicious and older, curly ones look wonderful in the vase. I set up an experiment, allotting 30 spaces each, in two rows, and planting the same variety in both of them. When the garlic were about half-grown, we set about cutting the scapes, but only from one row of the plants. At harvest, after trimming, we got 5 pounds of garlic out of the cut row, 6.5 pounds out of the one we left alone.