Install /e/ on device currently running Android 10 (specifically samsung s9)

So I’m really confused by reading all of this and other threads.
I started with a S9 with the latest software until January’s security updates, used the Easy installer to install /e/ and ended up with /e/ Android 8.1…
But what confuses me is that to upgrade to /e/'s Android 10 Q I first have to flash Samsung’s stock ROM to go back to where I was before and after that install the /e/ dev build that contains Android 10 manually??