What you're looking at is a proposal that actually got to private beta as a site, but simply didn't demonstrate enough interest or activity to continue on and open up to the public. When a topic on Area 51 interests you, it's important to first follow, then commit to that topic so that you receive an invitation to participate in the private beta. That would have been the ideal time to ask your questions.
However, the fact that it closed doesn't necessarily leave you without a place to ask, Home Improvement does take these types of questions provided that they're asked in the sense of someone doing some kind of project around the house.
It's relatively common for new sites to be sort of 'offshoots' of other established sites, where a group of users decide that they'd like to explore a very specific part of that site in a much broader sense. However, that doesn't make those questions any less on-topic for the site where the splinter originated.
If the topic happens to be completely unique in the sense that no site on the network currently caters to it, then something you could do is re-start the proposal yourself, and use the questions that you have as example questions of what would be asked on the site. Unfortunately, this precludes opening them up to be answered until or if it actually launches, but it's something you can do to show renewed interest in having a site for the topic.
You can also look around to see if there happens to be a site where the questions you have aren't currently on topic, but could conceivably fit well and be made on topic. Various parts of home automation could conceivably fit (for example) on:
- Android Enthusiasts / Raspberry Pi (as both are a popular control platform)
- Electrical Engineering / Arduino (questions about making / modifying devices)
- Home Improvement (questions about it in general, within their scope)
It would depend on your questions, but you can approach the respective communities on their respective meta sites and see if they think their scope would fit well with what you have in mind.
There's no easy way forward, unfortunately, since you missed the ideal time to ask your questions, but you're not without things you can try.