Ask HN: I built a Yubikey-based domain controller. Is it sellable?

I once worked in R&D where our competitive advantage was in keeping our customer relationships and intellectual property private, so we kept everything on-prem. No cloud, no SaaS, no WFH.

In my own SMB, I still self-host git, CI, chat, etc. I love the privacy and control, but I also needed to open these services to remote workers without exposing them to the world. So I built an appliance to protect my internal web apps by requiring user/pass+yubikey at multiple layers of the stack: L3 (p2p vpn), L4 (mTLS), and L7 (OIDC). The appliance is self contained (VPN, LDAP, NTP, CA, OIDC), like a classic domain controller, and it keeps servers safe from any users without an authorized hardware key.

I'd love to bundle this with an admin panel and sell it, but I forsee problems connecting with the right market:

* Clients who have meaningful IT budgets will require inter-operation with their legacy domain controllers. This means I won't have an MVP without major changes and lots of testing. It also puts my own product at risk: if Microsoft doesn't want to support my integrations, they can disable my product with a software update.

* Clients who are too small to have lots of legacy IT requirements will have small budgets and require lots of support. Some of these clients will grow larger, but this is a long game. I would love to support these clients but don't want to die for lack of revenue in the short term.

How would you sell what I've built?