So you will be able to come back on a tourist visa from Europe just have to be prepared to go thru the 15 night's quarantine and All the paperwork for COE etc.
It can't be month to month it will have to cover the entire stay of the visa stamp so if it's the stamp say's 60 days the. It's 60 and if the visa stamp say's 90 day's then it's 90 day's required. And let's be honest if we do take the whole CoVid equation out fo Thai who in their right mind wouldn't have an travel/health insurance under their entire stay just saying. Shit can happens every second CoVid or no CoVid.
Ok that's a issue I can't say with confidence what to do so I would for sure contact my local embassy ib the country of arrival first on phone but nonatter what I ask for the reply in a email to ahev as proof I. Case they say you are good to go but to be honest I do think you would need aleast a WP 3 form from the labour office in Thailand and that's some your company has to take care of unless it's you're company then it means you hope that helped a bit even it wasn't not a clear answer.