When I retrieved my broken stud-heads and found they were small, round and tack-welded in only three places, I decided I wasn't lucky enough for the other stud/bolts to be welded good enough to take drilling & tapping without breaking loose. Apparently others were lucky.
And as I said, backside-drilling of the crossmember gives one the opportunity to use a larger bolt of a stronger grade than stock. YMMV-