This WashXpress chain is all over town and I guess what DM is referring to.
There is one just west of the Big C on the West side of town. I washed a k ing size guest room bedspread/duvet/comforter or whatever the big heavy thing is called recently there and was impressed at the machine quality, size, convenient change, soap etc with folding tables etc.
All brand new Speed Queen gear.
There also is some type of App one might use with a QR code for each machine likely to pay instead of coins however I refrained installing and went old school with coins.
https://www.washxpressth.com/branch/
Hopefully the business model pays strict attention to management/maintenance and a clean/safe/easy environment. So far I am impressed. Yes, the largest washer is only 27% the size of KP's but it got the job done. Great for changing red drinking vouchers for 10 baht coins too.