I assume you’re the same person that asked this question on gnutons support discord chat. And the answer remains the same. No you cannot. You can request the router be added by gnuton, but on RMerlin’s side I doubt he’s adding additional support. Gnuton is in the best position to address additional support.
Fresh tomato, and openwrt, and ddwrt do not support this router.
If you attempt to cross flash firmware you WILL brick it. Their is protections against this but using anything other then Asuswrt-Merlin or Asuswrt-Gnuton and crossflashing may result in a broken router.
Sell it and or buy a supported router if these custom firmwares are what you require.