Let's face it, if the allium is going to seed the mother plant is nigh on useless so you might as well get something from it , unless you want the seed. It's a bit like eating the kale buds before you dig 'em and discard the plants, getting the most possible from the plant.
Gardening is an excuse not to do housework
Greetings from Salisbury
Qualified member of the Confused Nutter's Club