Well I built search bots at https://sb.nostr.band, which quote other notes. That's not the same thing that you're suggesting, but it's similar - a way to discover content that doesn't get into your feed naturally. I saw minimal traction, almost no followers on bots, and quite some complaints and mutes. But those might have been coming from the fact that they mention other posts/users.

I also have a list of some bot accounts here if you'd like to do any research https://nostrudel.ninja/#/lists/naddr1qqzyymm5wvq3vamnwvaz7tmjv4kxz7fwdehhxarj9e3xzmnyqgsrx4k7vxeev3unrn5ty9qt9w4cxlsgzrqw752mh6fduqjgqs9chhgrqsqqqafsp37r5k

There are also tools for twitter-to-nostr already, and quite some twitter-mirroring bot accounts: https://nostr.band/?q=rss+twitter&type=profiles

I think that experiment (at least a simple/stupid) version of it has been run and saw no traction. Maybe it should just get more sophisticated? 

 Ah those were indeed annoying 😂 

 Is there any particular reason why the feeds have stopped months ago?

I just followed your post’s link and those are from the first page.
https://nostrcheck.me/media/public/c1be12b7ada1dc092d54d896b7d54d705c77c683aa44bae2d4c5d32fb40ab8f0.webp 

 Could be an API thing, if Xitter is blocking the feed. 

 Twitter feeds aren't mine, IDK