Individual Home Buyer "Shared Equity" Co-Invest Market

Not even sure if the title is an apt way to describe this niche sector..

Someone recently introduced me to a market sector I had no idea even existed -- essentially private investment firms contributing towards an individual homebuyer's down payment with the promise of participating at 1.0x-1.5x of their "ownership %" upon the sale of the home. See Rook, Equifi, Unison.

I'm very curious how these arrangements work. I understand it at a high level, the investor captures the appreciation of the value of the home, but how do these things work mechanically? The investor is essentially a "common equity" holder and would get wiped out in a foreclosure scenario right? What happens if the home is sold below cost? Do these investors have blocking rights on a sale? What happens if the homeowner stops making payments? Seems like a ton of risk to the investor without a massive upside... but I suppose the strategy is to write 100s or 1,000s of these smaller checks so the winners offset any potential losers?

If anyone has exposure to or experience in this sector please chime in. I don't have any skin in the game on this, I was just blown away that the market for this exists but I guess it makes sense if home prices continue to increase and interest rates stay relatively constant. Smells like '08 in here..