To be frank, one of the main reasons I personally don't like promoting servers is because people with the same gamemode start hounding me about why their server isn't official despite having more or less the same merits. Aside from Daydream RP (which I promoted due to its novel use of Dogecoin when released, along with the admins being smart), none of the servers repeat gamemodes.
If your server uses a gamemode that isn't already on the official list, it's likely because I either haven't been able to review it or my observation of the administrative staff or gamemode implementation raised concerns.
This thread is also a perfect example of why I hate touching anything involving the official list. If I promote a server that isn't yours, it must be due to nepotism. By itself, this is also an attitude that would make me reluctant to go anywhere near your servers.