The links were actually unnecessary and, beyond one sentence about welding in almost a combined half hour of video, interesting but totally irrelevant to this problem. Your subsequent post, while insulting, was much more helpful than either video, and I just honestly (and bemusedly- I find it kind of funny) don't understand why you didn't just post that in the first place. Or at least just not give me snark about not finding that one sentence in an off-site video without more information than "Check out this thread." Even "Check out the videos in this thread" would have been clearer. I'm honestly just bewildered why you would be snarky about how I read a whole thread on an unrelated topic that had no useful information in it but didn't bother to watch over 25 minutes of video in said unhelpful thread to hear one sentence. It's like saying something is in a room, then getting pissed because the person didn't spend 15 minutes searching every pocket in a pile of clothes in that room to find the item in the pocket of a jacket in the middle of a pile. It's the kind of thing I end up laughing at myself about when I accidentally get in that situation with my husband.
But yeah, if you can't respond to a question of mine without talking down to me or disrespecting me, please don't bother responding to me at all. It's not helpful, I'll call you on it, and then we'll both be unhappy. And where's the point in that? Just keep doing your thing, and I'll eventually figure it out. I just wanted to find the answer more quickly. And thanks again for the information on PML.
Oh, and just to put it out there for anyone who comes across this thread, you have the fourth option of just not welding your export. It's a lot less convenient (for instance, smoothing is a problem), but you can work with an un-welded mesh. Considering the fix morphs I need are facial (only have to worry about the head/jaw join), it might not even be an issue. Certainly my main reason for not using the Morph Tool, which was working around the eyes, won't be a problem.