Honestly, that "it'll grow back" advice is how people end up with a split trunk during the next big storm. Fast growth often just means weak, poorly attached new branches. Seen it happen where a lopsided trim leads to a huge, heavy limb developing on the thin side, which then just snaps off under its own weight. That uneven structure becomes a permanent weak point. Better to even it out now while you can still guide the shape, instead of hoping for the best.