Ineligible For Channel Memberships

I have a two part question...

First, do people have any success with channel memberships (my channel is ~130k subs)?

Second, how do I make my ineligible channel eligible? It's failing because it has "a significant number of ineligible videos." What's a "significant number?"

To give some backstory, I own a niche media company. We hosted a lot of "viewer videos" in the beginning (early 2019) that didn't have cleared music, but have moved away from that this year. I still host videos with claimed-music as part of yearly advertising deals we have with brands, but I wouldn't consider it "significant" compared to the original content we create. We do have a loyal fan base, so if channel memberships are actually successful for medium channels annnnd I can remove/mute enough older videos to qualify, I'd pursue it.

Thank you!