I have a brand new router AX3000T with ESMT Chip. Its a RD23 with 1.0.90 (INT) firmware.
Try to install with xmir-patcher-main and getting in menu 2 get this message : "ERROR: Exploits arn_switch/start_binding not working!!!"
Please share link how to downgrade ... lot of information at web page.
Read about u-boot but im not sure about it.
My router was with 1.0.30 and i think i fail updating to 1.0.90 because now im not able to downgrade from MyWifi menu ( "For security reasons, selecting to upgrade to firmware whose version number is lower than that of the current one is not permitted")