I would recommend LBRY (or Odysee as they are the same thing essentially) : https://odysee.com/ https://lbry.com/ Odysee also has a great feature where you can do a video sync from your yt channel if you don't want to deal with the hastle of downloading and reuploading every video individually. Odysee also has a reputation to be reputable on the site, as I personally have had a lot of user submissions come in through this platform.
Another alternative is peertube, https://joinpeertube.org/ I really wouldn't recommend this platform unless you plan on doing ONLY mobile runs, as you can upload your videos through the Newpipe application (Highly recommend this for mobile no matter what platform you end up choosing).
Overall, LBRY/Odysee would be the best options personally, but there are a few other options such as bitchute and peertube. They just tend to be less known than Odysee and have some usability issues.
Some users also don't have the ability to upload to YouTube due to region restrictions. I'm not sure if ggboi is in one of these regions, but the game moderators shouldn't force a video platform unless there's a very specific reason for doing so (most of the time this would be twitch, to show full broadcasts for additional proof).
I changed most of them when you submitted your runs, I may have missed a few but I'll try to go through and fix them.
First of all, this sounds like attempted preferential verification, which is pretty frowned upon in most situations. The one case that it could be useful for, like you said, is rejected runs, but then again it's pretty easy to scroll through the list and take quick glances at the rejection notes.
You can request new games here: https://www.speedrun.com/knowledgebase/supporthub/request-game-or-series
Or request a position of mod from an inactive user here: https://www.speedrun.com/knowledgebase/supporthub/request-moderation