no you don't. Only if you've been in Thailand for the last 2 years on repeated covid extensions. Then maybe you'd have problems returning in under 24 hours.
yes it is open. And can go and return within 24 hours. Most people apply for their TP before they leave Thailand. Lao opened it's borders on the 9th. A border bounce is to re-enter Thailand and get another 30+ days in the Kingdom.