Looking for a practical solution myself.
Peak Torque's 180mm adaptor should work, you'd use his adaptor AND a ltwoo adaptor (probably the 140mm one). Issue is, it's very expensive for what it is.
There's another website in the US selling a similar thing, also very expensive (easy to find on google from memory). Website indeed focused on gravel / bikepacking things.
I have found a 10$ adaptor for the rear, so i'm running 180mm at the rear, which is helpful, as it takes longer for the disc to overheat and scream.
The fork solution is proving elusive. An adaptor for regular shimano brakes (they're standard flat mount) is available for 10-15 eur, but it doesnt work with ltwoo. i tried