IMHO, Mega isn’t a good choice for use with Duplicati. We had a lot of problems with connections, Mega block our account (old account that was working) and they didn’t notify us. When we send an e-mail to support, they answered: “It looks like you are using some kind of third-party tool. Please note that these tools are insecure and do not fully implement our cryptographic protocols, therefore if you cannot access your account, that could be the reason”. Finally they told us that they don’t recommend using Mega with third-party tools.
In addition, backups are much slower than with other services. I think because of Mega encryption/decryption process.
We now use B2 Storage.