Thanks for your feedback, @tkohhh, @Klutz , and @mburyakov, and welcome to PhotoStructure!
Yup, thanks for being patient! I added some more details about what this work entailed here: Initial library build - processing pauses - #2 by mrm
Absolutely, and I think keyword editing is the lowest-hanging fruit for “tag editing”: it arguably gets this feature request addressed, at least as a first pass.