On: Have you ever seen soldering this close? [video]

[dyno12345]

you have to have the right amount of solder on 100% of the pads for this to work correctly though

[avar → dyno12345]

Do you? I'd imagine you can have too little on some of the pads, such that the melted material doesn't make contact.

As long as others pads have enough they'd pull the BGA into place, and at that point those pads would make contact and complete the solder.