I suggest that you have a chat with someone who does this every week and knows what is possible - on the ground.
Immigration offices can vary from office to office in how they handle things. What works at one office, sometimes does not work at another.
Herbert has been taking people for 'border bounces' for 20 years. He tends to be aware of the latest local 'rules'.
https://hdvisa-thailand.com/
Visa runs are usually to Malaysia.
By the way, quickest is usually not the cheapest.