You do not need to own Elite on steam, you do need to have Steam VR and windows mixed reality installed.
If you launch Elite from FDs launcher, Steam VR and WMR should start automatically, I've done this for the last 18 months.
(as Iain L data you can start them manually but it's not necessary, there is a setting somewhere in steam/wmr to auto launch VR when it's asked for)
Edit: and use EDProfiler, (thread VR sub here), it's great