Will a Bcache disk setup survive a reinstall?
 

All my steam games are installed on a Bcache (read-cache only) setup:
- Backing device: 1TB HDD
- Cache device: 256GB NVME

I presume it will be fine because read-cache only?

Its not the end of the world if it doesn't, but re-downloading nearly 1TB would be annoying.

As long as you don't touch the backing device you can recover the data even without the Bcache mount. See https://www.kernel.org/doc/html/late...de/bcache.html but it should be fine on an upgrade. For extra peace of mind, make sure you back up the config files under /etc/lvm.