[CamperBob2]

You're not gonna be able to pick-and-place anything with hundreds/thousands of parts at a hobby price point.

LitePlacer is almost there. IMHO the key is recognizing that production-oriented machines need to be fast, while hobbyist/small-shop prototyping machines don't. If I need to stuff a complex prototype board with 500 parts, I literally don't care if it takes all day and all night as long as I don't have to do it. Obviously production shops don't have that luxury, but I do.

Really, the only unsolved problem (at least at the 0402 and up level) is loose part pickup and orientation.

[mng2]

Agreed. Being a human pick and place for anything more than low tens of parts is incredibly unfun, and paying someone to manufacture one or two doesn't really make sense. I don't care if it takes a few days, I'd rather not be sitting for hours wearing down my fine motor skills and eyesight.

[thesmok]

If it takes more than an hour to place the components, your solder paste will likely flow all over the board and it will be pointless to reflow it.

[CamperBob2]

That's not a big concern for prototyping. It will reflow just fine. There might be a few solder balls rolling around afterward, maybe a bridge or two. Most of the time, this means your stencil apertures were too big, or that the cut-rate Chinese solder paste wasn't the bargain that it looked like on AliExpress.

Slump is a problem if you're trying to run a six-sigma process in a factory, of course, but that's not what's being discussed here.