I'd like to see LR Classic-like plugin support for things such as https://regex.info/blog/lightroom-goodies or https://www.negativelabpro.com/
Primarily on Desktop, but if you can do it on Mobile and Web somehow, more power to ya.
I know this past thread was marked as solved:
https://community.adobe.com/t5/lightroom-ecosystem-cloud-based-ideas/p-3rd-party-plugin-support-for-... but it was really only for the round trip feature of editing raw files.
Searching on here is difficult so if an existing request exists, my apologies.