My internet speed is more than sufficient to accommodate downloading 4k movies in a hour so title updates etc. are a walk in the park.
I use Sonarr and Radarr for my movies and this takes care of the titles and renaming. Previously it has worked. but stopped somewhere in 8.x I forget which. So, for 9.x I simply made a clean install hoping that the problem was software related and would go away... sadly, it didn't.
There are significant scraper differences between Kodi v17 and v18 - the main one being the default scrapers use a different DB site. And just because you've got a super-fast connection doesn't mean the DB websites don't throttle their responses to ensure manageable load on their web tiers (and they do this). The scraping experience in v18 is quite a bit slower than v17 but there is nothing you or we (or Kodi) can do about that. The main goal was to continue have a scraping experience (instead of no scraping).