What are the requirements for a 1-year extension on a Non-OA retirement visa in Thailand?

Hi everyone, I'd love to get some advice from people who have experience with the Thailand retirement visa.

Here's my situation: I'd apply for a Non-OA (retirement) visa from my home country — the 3-month entry type. Once in Thailand, I'd extend it for a full year at Immigration and file a TM30 for my rental address. I'd sign a lease for roughly 5–6 months, which covers the period I'd actually be staying.

After that, I'd need to return home for family reasons — but I'd come back before the extension expires, get a new place, file a new TM30, and apply for another annual extension. Before leaving Thailand I'd also get a re-entry permit so the extension stays valid while I'm abroad.

I have two specific concerns I'd love your input on:

1. Does Immigration require a lease that covers the full 12 months when granting a 1-year extension? Or is a shorter lease (5–6 months) acceptable? I've heard some offices ask for proof of address for the entire extension period.

2. During the months I'm back home, there would be no active TM30 on file for me in Thailand — since my lease would have ended and I wouldn't have a new address yet. Is that a problem? Does Immigration expect a TM30 to be on file at all times, even when you're not physically in the country?

Any firsthand experience or advice would be really appreciated. Thank you!