Moved to electric eel what to delete in app data

Hi
I have moved to electric eel and enjoying learning docker but in my app dataset there seems to lots of stuff left over from the old system. Just wondering if anyone can help with what to delete.

Thanks

Seems similar to my issue Deleting apps from UI is not deleting app data from ix-applications dataset - #2 by Trudge

Many thanks for your help think I am good with it now

New here and trying out the Electric Eel Beta. Apps migrated well except a custom app. Used new custom app to install logitech media server again and all good.
Followed @DjP-iX advice and deleted the old unused ix-applications dataset. Again all good.
I am impressed but a bit confused by the move to /mnt/.ix-apps. Does this now mean that despite choose pool being set in the App Gui to an existing dataset that the docker base ignores that and uses the boot pool? My boot pool is mirrored 256GB nvme so not concerned. USB boot might be a concern or am I incorrect about boot pool.

/mnt/.ix-apps is not in the boot pool. It is still on the applications pool, there is a mount for that. In my zfs list, I see:

applications/ix-apps                                               5.07G  17.4G   116K  /mnt/.ix-apps
applications/ix-apps/app_configs                                    640K  17.4G   640K  /mnt/.ix-apps/app_configs
applications/ix-apps/app_mounts                                      96K  17.4G    96K  /mnt/.ix-apps/app_mounts
applications/ix-apps/docker                                        5.02G  17.4G  5.02G  /mnt/.ix-apps/docker
applications/ix-apps/truenas_catalog                               53.0M  17.4G  53.0M  /mnt/.ix-apps/truenas_catalog

So, does that mean we can put .env files in /mnt/.ix-apps/app_configs/appname/versions/1.0.0, where I find the compose yaml? And other files I might want to copy in if using dockerfile_inline? Or will those go away or somehow be destroyed by the ui?