Unchecking "host path validation" allows you to install the app, but whatever I do the app (Emby in my case) cannot read anything from the SMB shares. It keeps giving permission denied in the log.
I have an "Apps" NFS dataset with an emby dataset subfolder: apps/emby
I have a "Media" dataset which is shared via SMB. I can mount it for the app and it's visible in the app, but it can't read any of the SMB data (subfolders, ...). I've tried adding in the ACL editor "apps" owner (user & group), added the apps user, ...