We had the house rewired and included some Marmitek X-10 automation BUT this standard is no longer supported as the manufacturer has gone out of business so try not to build in obsolescence.
But when you go to the Din rail modules like LD11 they are out of stock and have been for over a year.Seems to still be on sale:
I took one of my modules apart and the little bit of plastic that throws the switch via the solenoid had broken and I couldn't see a way of fixing it, or getting all the bits back in the caseIt was brilliant on a simple level. Very cheap. All one needed for lighting, aquatics and did not clutter the airwaves but as you say, obsolete.
Now the tech gobbles up airwaves, is far from cheap and too complicated. Like new MHs once it goes wrong very tricky to diagnose.