I have the old (1979) Swedish AGA valves in my radiators and the eQ3 MAX! thermostats wouldn't fit without two separate adapters for each radiator. That got quite expensive, doubling the price for exchanging thermostats. So I designed this adapter.
Works very well and would probably fit other M30x1,5 thermostats as well. I have tried with the Comet and that fit also.

Print this in some plastic somewhat resistant to heat, I used 3D Prima Prima Select PETG, or it will get deformed.

I printed it upside down from what you see in the picture using supports from the build plate. But be careful not to get supprort in your threads, that can ruin your day.

Enjoy!