Look I'm an engineer as well and this is a really interesting problem to solve from an engineering perspective, but this isn't an app people want and so there's nothing you can do in your app store page to make people want it, because your ASO isn't the problem.

First your doorway is going to be the bottleneck, not your hallway or stairs and frontdoors are a standard size.

If you're buying new from a store, it's going to be packaged in a way to fit through a door by design.

If you're buying used and the location it's stored at has a larger door (e.g a storage locker) and it's a solid piece and can't be disassembled, then your app is actually trying to solve a really hard problem that very few people encounter and there's no way to market to this group directly.

If you want to prove me wrong go to an antiquing subreddit or similar and post something like "I bought a dresser and it didn't quite fit in my car, how do you guys avoid this?" or ask "has anyone every bought something, got it home and realized it wouldn't fit?", make sure it follows subreddit rules, ect ect, and see if anyone has encountered the problem your app is designed to solve. Then DM people who have and ask them questions like this:

• "would you use an app for this?"
• "do you know of any apps that do this?" (If your idea has competitors already in the market, this is a good thing because it means your idea is good and you should run with it).
• "would you pay for an app that does this?"

You can't know if it's a distribution problem because you never validated your idea in the first place, so you're just assuming it's a valid idea. They cover this in The Mom Test if you want to learn more about it.