What should I consider when planning a visa run from Thailand with a multi-entry tourist visa?

These are the common found requirements for the 30 days extension of stay at your local Thai Immigration office for 1900 Thai baht. Be sure you have a TM30 address registration on file with Thai Immigration.

I had replied to you when you sought to Post this an hour ago.... Asking for clarification on what kind of multi-entry Visa you have ?

DO YOU HAVE A METV MULTIPLE ENTRY TOURIST VISA which you obtained from your Thai Embassy in Germany BEFORE you flew to Thailand?

Or did you buy a SINGLE ENTRY TOURIST VISA SETV while you were in Germany?

I think you have a SETV... And you were STAMPED in for 60 days when you arrived into Thailand in November 2023... and in January 2024 you got a 30 day extension of stay at your local Thai Immigration office for 1900 Thai baht.

IF that is what you have...

Then you can do a simple LAND BORDER BOUNCE to get a NEW Visa Exempt Entry into Thailand. Gets you 30 days STAMP on arrival plus One 30 day extension of stay at your local Thai Immigration office.

As you say that you entered Thailand in NJ ibe

Pay attention to the validity date of your visa and time your border crossing as close to the last day of that as possible. You may struggle to get another tourist entry after that whether on a tourist visa or visa exempt

If on an METV, yes, make a border bounce as close as possible to the expiry date of the visa, it is valid for 6 months from date of issue, and get your last 60 day stamp on entry, then extend 30 days at immigration. After that you'll need to leave or if possible transition to a different visa in country.