Beware that Litestream on PaaS has safety concerns unless you can get your PaaS platform to guarantee that the active app instance is terminated before a new instance is booted. Litestream doesn't turn SQLite into an multi-master distributed system.

If two copies of the DB accept writes at the same time, Litestream will just send backups to two different backup generations, and when you restore you'll only pull down one of those generations and won't receive the writes that landed in the other generations. All of your writes will still be in S3, they'll just be peppered across distinct backup snapshots and you can't get all the data back unless you separately restore all relevant generations and manually merge the restored databases.