a ) full-disk encryption is needed when the information is on a single disk. We used this in the original ecloud.global (LUKS). It offers no extra protection in this kind of incident in regards to the current server-side encryption (since once the disk is mounted, the files are unencrypted to the application).
b ) we are always open to exploring alternate base platforms for our Murena Cloud but the choice of Nextcloud was taken long time ago and it wouldn’t be an easy move.
Just consider this comment on Seafile:
The client side encryption does currently NOT work while using the web browser and the cloud file explorer of the desktop client.
Users want E2EE but they rarely want to give up any functionality like sharing, collaborative real-time editing of office docs, web access… nothing of which is technically impossible but it’s just not available out-of-the-box and bug-free as of now. So we will continue exploring the possibilities knowing it also needs to be integrated into eOS and with a seamless transition for existing users.