Anonymous participant 213 I've not heard of immigration at airports or land borders asking for proof of work contracts. That would slow down processing a lot. You must be referring to in country extensions.
They might ask you what your purpose of stay is when re-entering (or even entering the first time) but that's about it.
Out of curiosity, I asked one agent to give me a quote, who was charging 27,000 Baht to help with an application done in Vientiane. 30,000 Baht if you needed their lodging and driving service while there. I felt that was already quite expensive.
This soon ballooned to 50,000, then 100,000 Baht. Crazy amount of money.
Assuming there's no scamdemic similar to Covid between now and 2030, you can continue to exit the country every 90 days without a reporting requirement.