I need a second opinion on the following setup - hope somebody can help

What we do now:
Backup VM's from our SAN to a dedicated Veeam storage server using direct backup (DC). The backup method is Reversed incremental.
What we need to accomplish:
Copy our daily backups from the Veeam server to S3 (we have a file based backup solution and a 1 Gbit connection to Amazon EU in place for this).
I have been running a test with above for the past month - i.e. I changed the backup method for the jobs to forever incremental (with conversion once a week).
This works pretty well (transfer speed to S3 is approx. 300-400 Mbit) but I am a Little bit nervous about using forever incremental without active full backups.
Anyone been doing forever incremental for a long period of time (without doing active fulls) - and then do restore tests?