Another nice thing you can do if you use the multi-partitioned memory overlayFS approach I mentioned earlier is you can make /var/docker be a symlink to your read-write data partition. Obviously you are going to have problems using docker with the standard memory overlayFS approach.

Also nice, is you can make your data or other partitions be encrypted. I've done this before. On the Pi 5 you can use the standard encryption as there's hardware support. On earlier Pi's you can use the encryption used for android. This does means there's a manual step in the startup for you to enter your encryption password.