A lot of these are starting to show up on Amazon.
https://www.amazon.com/Mounted-Bathroom-Pressure-3-Setting-Handheld/dp/B08QF7QFJX/ref=sr\_1\_150?crid=2GKE2F63XD3KG&keywords=shower+rough+in+valve&qid=1644256643&sprefix=shower+rough+in+valve%2Caps%2C164&sr=8-150