Anybody implemented 2x FGWDEU-111 controling the same circuit?

Ladies & gents,

exploring Fibaro devices, it seems that the WALLI devices are doing the job
On regards of the dimmer FGWDEU-111, I found connecting instruction to have 2 dimmer controling the same circuit.
these instruction are asking some “grouping” steps in the Fibado box and tuning of both the switch side of the device and the dimmer side of the device.

Anybody have implemented this successfully with Homey ?
is the grouping available in Homey ? (or is this needed ?)

what happened if the homey is down, are the dimmer still operationnal ?

best regards