That's the point. With start-ups you probably also get liquidated.

That said, you should obv. adjust your benchmark leverage according to the risk profile of the fund (/start-up).

So. For example, if you invest into a single start-up, you should probably get a 90% failure rate. A simple approximation for leverage would be to check the historical price chart of bitcoin and see what kind of leverage will not get liquidated 10% of the time (historically). You can do other approximations as well.