If you invest $100K at <$1M valuation pre-revenue in 100 pre-Mittelstands, 1-5% of those companies are going to get to $100M+, 10-30% will get to $10M+, and 50%+ will get a positive exit.
There is a robust buyout market between PEs and corporates for these companies.
Yes, this is a form of venture capital. But most VCs today would not consider pre-Mittelstands VC-backable startups.
This post and my last one We Need a Middle Class for Startups (https://neilthanedar.com/we-need-a-middle-class-for-startups...) make the argument to VCs that they can get big exits and returns investing in Mittelstands.
You say "pre-Mittelstand", so I guess it's not about investing in companies that are aready Mittelstand (and effectively lifting them out of that) either.
From there, they will have many exit options, including corporates, PE, and even IPO.
I don't believe there's anything in the Mittelstand definition that prohibits exits.
I'd target this Y Combinator for Mittelstands accelerator at the $0 to $1M stage for pre-Mittelstands.