Which radio switches for a triple stair switch in the handrail?

Welcome,

i am looking for a solution to my problem.

I have a designed triple stair switch in the stair handrail
1) downstairs switch turns on/off the light in the corridor upstairs (as a stair button), turns on/off the stair sconces and the stair lamp - stair buttons,
2) upstairs switch turns on/off the light in the upstairs corridor (as one of the 3 buttons), turns on/off the stair sconces and the stair light - stair buttons.


I would like to know if you can suggest me a solution to this arrangement....
supposedly the wiring is done, but unfortunately I have not been able to find switches that would require less than 4m deep box .... unfortunately the handrail is 2cm deep and there is a half circle ....

I was thinking about radio switches ... only, will they work with traditional switches? or will I have to replace the whole circuits?

e.g. in the upstairs corridor (where I already have 2 switches installed) to replace the control unit as a whole with a radio control, will these work together somehow?

thanks
kind regards

Anything is possible, there are circuits that fit into 60 cans, but are they definitely radio.
Consider bistable switches/relays

Even in AVT KITs you can find a solution.