I’m getting the feeling that you already have sun ml13 wheels
or something. I’d just run a 32 or 35mm tire on it and be done. It’s going to be more cushioned by a 32 by far than a 23.
https://www.bikeforums.net/bicycle-m...15mm-rims.html
The bike mechanics on here all say it’s ok to run a 35mm on a 15mm rim. I’ve ran a 55mm on a 19mm rim without any issues myself. 32mm on a 14mm rim will be just fine.