Not an answer but please dont use duckdns. It has a 600 ms ping and very frequent outages. Using cloudflare is free and is insanely fast and reliable

Daily restic backup of OS and Data to Backblaze. Cant be happier

Remember that cloudflare will see your traffic, Even with an ssl certificate.

.space is the only answer, have to buy that though

Backblaze is great and transparent

Restic is great for that, deduplication and snapshots as well