Volunteering at a SaaS portfolio company in operational capacity

Hey y'all!

I'm currently a senior product manager @ Microsoft leading revenue growth initiatives for M365. I'm applying to MBA schools with the hopes of running my own search fund and acquiring a SaaS company afterward. I was just talking to a friend who is currently running a search, and he recommended I should volunteer at a portfolio company pre-MBA just to see what running a company is like post-search. Does anyone here know where I can find a list of SaaS portfolio companies, so that I can reach out to them with the hopes of taking on a volunteer project or two? Any help would be extremely appreciated. Thank you!