@girish weird, "./" was the first thing I tried when it didn't on its own but there again it threw me an error about command not found and minio-credentials not being a folder. I resorted to trying bash in case I got it wrong and that's the only time it at least tried to run something (but ran into those errors).
But have just done it again and it worked fine, I must have done something wrong the first time.
Sorry for reporting a non issue and thanks for getting back

taken from https://my.example.org/#/system

/dev/sda4 mounted at /home
This ext4 disk contains: ...

@girish Thank you, awesome replies!

Fixed in https://git.cloudron.io/cloudron/minio-app/-/commit/6eb1e7b4b9bbb3f8a2c1e44ac6d78b232ed79162

AFAIK, there is no such limitation. Indeed, I am able to add as many users as I want:

girish@benton:~/tmp$ ./mc admin user add minio newuser newuser123 Added user `newuser` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser1 newuser123 Added user `newuser1` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser2 newuser123 Added user `newuser2` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser3 newuser123 Added user `newuser3` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser4 newuser123 Added user `newuser4` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser5 newuser123 Added user `newuser5` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser6 newuser123 Added user `newuser6` successfully. girish@benton:~/tmp$ ./mc admin user add minio newuser7 newuser123 Added user `newuser7` successfully.

Then:

girish@benton:~/tmp$ ./mc admin user list minio enabled newuser1 enabled newuser2 enabled newuser3 enabled newuser4 enabled newuser5 enabled newuser6 enabled newuser7 enabled newuser

@RoboMod Sure, sorry for the no response. From the logs in the other post, the error is Message: Connection timed out after 300000ms HTTP Code: TimeoutError. Maybe the server becomes unreachable because of some network error? Is that possible in your setup?