I'd like to know as well. I am considering 3.11 or 4.0 to deploy later this month or in June.
Exactly as you described! One installer to rule them all :-)
You go first with installation of FSDB, providing it credentials and access to your Orion SQL DB, then once finished you go to your main server launch same installer there, select you have separate FSDB and provide IP/hostname of that server. If you have some additional pollers, you proceed with upgrading them once you finish upgrade on main poller.
Note: You can migrate your existing NTA 3.xx flows from SQL during CW run.
we're just releasing new version of NTA: NTA 4.1.1 SR Release Candidate available
and to anybody who wants, we're offering assisted upgrade with our engineering team on goTo meeting. just respond to @michal.hrncirik directly and I'll contact you about details.