I think you're looking at the low hanging fruit rather than digging for the gold that is surely inside these goldmine companies...
What I recommend is to advise all of these startups is to master internet marketing. It's the one skill set that once mastered, can and should give rise to new business strategies that can achieve that which you really want, which is an exit at 10x - 100x whatever their current valuation is...
Literally ask them and their teams to spend 4 hours a day minimum learning about internet marketing, starting with the fundamentals, the pirate metrics...
AARRR - google it if you don't what these are....
Have all your startups declare these metrics, then have them focus on ONE of these metrics, set a goal that is achievable but shows real progress. Give them a goal for every quarter...
And don't worry about anything other than these startups meeting these pass/fail goals
