Optimal 2.4GHz Radio configuration for Coverage and Quick Startup

I have the GLi.Net MT6000, I am using it with the latest OpenWrt 23.05.5 in Access Point (AP) mode.

Both wireless radios are configured with mostly defaults, I have assigned a Channel instead of using Auto, and set the Transmit Power to Maximum (for my country US).

What would be the optimal configuration for Coverage (max signal power) and Quick Restart (I think by predefining a channel it doesn't have to scan at boot, but I might be wrong).

Please any guidance to information or link or feedback will be appreciated, thank you

I prefer to use fixed channel, not auto. It may not be faster but better.