Dankness
tldr: Instead of seeing the resource reloading screen twice sometimes when switching a proxied server with a network-wide pack, you won't see it at all.
1.20.2 introduced a new protocol phase, being the configuration phase. In it, you can send the client resource packs before they enter the world and also better communicate server switches. Unfortunately, the 1.20.2 client forcefully unloads the current resource pack, which means on server networks with network-wide resource packs, the pack will have to be resent on every server switch, resulting in two loading screens.
... This mod hackily "fixes" that by just not reloading the resource manager when re-entering the configuration phase, as well as ignoring packs that have the same hash as the already loaded one.
Even less loading
If you want to get rid of the resource pack fade effects and other screens, you might want to check out this as well: https://modrinth.com/mod/forcecloseworldloadingscreen