Thank you mwittig for your reply.
I do have the remote and I might open it up to reverse engineer in the end.
Using Shelly is NOT an option, I need a more versatile leading and trailing edge phase cutting device, which so far Shelly does not offer. Also sonofff didn’t seem to offer such a dimmer so far to my knowledge.
This is so far the only ready made device I found for my purpose for a reasonable price.
I am building a 5 channel dimmer my own utilizing FL5150MX chips but this will be a DIN Rail Mount device. The benefits of the S1-B is not only the price but also the size, since just like the Shelly it fits easily behind a switch in the wall.
The fact you mentioned about the possible lack of a back channel from the S1-B to remote controller unit is indeed another thing to keep in mind, which might make it less interesting to use in an automated environment