I found this answer on a thread about flight price, so is it actually risky to travel by air if I have a long history of stay in Thailand?
"Posted December 3, 2022
Since you say fly and come back (no mention of a visa application) i assume you are either (i) holding an unexpired multiple entry visa; or (ii) hoping to receive a visa exemption on your return.
If you have a multiple entry visa, a same day return from Bangkok to Kuala Lumpur (around US$200 on Air Asia) is one option. From Chiang Mai, leaving Saturday to Hanoi and returning Sunday can be cheap (under US$200) if you are eligible for visa exempt entry to Vietnam.
If expecting a visa exempt entry, be careful! Depending on your immigration history, you risk a denied entry, and a border bounce by land could be more prudent. That does not necessarily mean a lot of overland travel. For instance, you could fly to Penang, take a taxi to Hat Yai airport, crossing back to Thailand by land, and fly onward domestically to your final destination."