I just posted a request on the linuxserver.io forums (you can find it here https://forum.linuxserver.io/thread-585.html) about getting a Minio docker created.
I found a blog article discussing the use on Minio and duplicati to mimic Crashplan Home.
I will likely be combining duplicati with an Amazon S3 service to get the cloud backup portion taken care of; but that does not cover the Crashplan server I had running locally and was also backing up to. I believe I can get M
Set your storage type to Webdav, fill in your nextcloud server address and port, set path on server to remote.php/webdav/backup-folder-you-want-to-use (NOTE!!! - NO pre or post /) for this backup set. Each backup MUST have a unique folder. Nextcloud user credentials each have their own tree, so as long as you have unique users for your backups, each one could be at remote.php/webdav/duplicati or something, but if you use the same nextcloud credentials for 2 backups, make SURE you have different