Are older senses of "anent" still alive in any dialect?
I have not run across this term in my own dialects of English (American, West Coast), but I did find this in Wiktionary:
anent:
(obsolete) Against, in front of.
(archaic or dialectal, chiefly Scottish) Concerning, with regard to.
I am wary of blindly accepting Wiktionary as a source, but it may be that anent has fallen out of usage entirely. However, in 1913 it was still listed in Webster's dictionary, so the drop from usage may be after your last available cited quotation.
HP Lovecraft was still using the word anent in his letters to colleagues in the 30's. But he was well known for his archaic diction. So I'm not sure that's the best example.
Very much actively in use in contemporary Scottish writing & letters. Usefully short for tweeting, & part of a mild "Scots" revival, consequent upon a tide of constitutional politics in Scotland.
The General Assembly of the Church of Scotland has just decided to stop using "anent" in Church legislation. I'm a Scots lawyer and, although I don't think I've ever used "anent", I occasionally use "thereanent" in correspondence or formal documents.