Yes, very taboo. ;-))
Many trees will have brebas, including VdB. The question generally is how many and if they are worth the bother. For me, VdB will have about 1% breba or less, compared to the main crop, s it is insignificant, and they usually ripen during cool months (June) so aren't that tasty or sweet, so I ignore them. I don't pull them off, though most do not form because of pruning. If you have a shorter growing season, they may misdirect energy and delay ripening of you main crop, but suspect that may be more true for varieties that have a heavy breba crop. Don't really know.