I seem to have found some stability — my last crash was five days ago.
I believe the last tinkering I did, was the deletion of the mnojpmjdmbbfmejpflffifhffcmidifd directory, although I also see by looking at my Trash, that I did it twice: once on Feb. 10, and again on the 14th. My last crash, according to brave://crashes, was on the 15th.