You can run complex compose apps on EE directly, but volumes will go to the apps pool selected.
If you want you can overload the compose file to redirect the volumes to host mounts etc.
A clean way is to use Docker in Incus, and in fact, you can delegate a zfs dataset to the incus container, although this is not directly supported by the GUI, but would perhaps work well.
With Incus you can set the virtualization pool separately to the apps pool, but if you wish a secondary storage pool that will not persist across TrueNAS upgrades.
You may want to look at this thread