"Off Market" Franchise Opportunities

I’m curious if anyone here has experience getting connected with “off-market” franchise opportunities. By that I mean businesses that are not publicly advertising franchise opportunities, but may be open to expanding slowly with the right operating partner or franchisee. Brands that are high-quality, selective, and more relationship/referral-driven than traditional franchise sales. For context, my business partner and I currently operate multiple franchise concepts across multiple states and come from a strong finance/operator background, so I’m thinking about this from the perspective of someone who could potentially be a serious candidate for the right brand. Assuming someone is qualified to be in that conversation, where would you start? Would it be through franchise attorneys, PE groups, existing multi-unit operators, brand consultants, or direct outreach to founders? No offense to franchise consultants, but my experience is that most are understandably focused on brands that are already “on market” and paying commissions. I’m more interested in how people find the quieter, more selective opportunities before they become widely marketed. Would appreciate any thoughts, introductions, or examples from people who have seen this done well.