I use Lightroom to process my photos, then upload manually to AS. Occasionally a spelling error slips through. Lightroom has no spell checker (PC version).
This just happened to me and I had to generate a ticket on AS since it seems they don't allow editing of titles after a file has been approved.
Two questions:

1. I heard there is a Lightroom plugin for uploading to AS...does it have a spell checker? (I gave up requesting Adobe to add spell check to LR).
2. In general, what do others do to avoid this issue without adding a lot of overhead in the file generation/upload process?

You can and edit the files after they have been accepted at Adobe Stock.
From your dashboard click on the file - then click on the field your want to change then click the edit icon.

But to solve your problem - First upload to a site that has a spell checker, when you see a problem go back and fix it before you upload anywhere else.

It's a good idea to obtain suggestions from Adobe, SS and Pond5, then you add yours, check and store the metadata for other sites.