There’s always a link to the source code in F-Droid, mostly you’ll find a way to open an issue with feature suggestions there. (as is the case for this project).
Yes, I have found the link to Github after. There I read a suggestion close to mine, Option to enable wifi · Issue #6 · MBach/AutoAirplaneMode · GitHub with a command line to avoid WiFi with airplane mode. So my problem is doubly solved!
Thank you, I post to fast!