Danfoss valves and TRVs on 2 pipe vapor system

jessestaton

Hi all,
Looking to better balance our 2 pipe vapor system (around 2 oz) with installed orifice plates. The valves have all be replaced over the years with on/off type (all the metered valves but one are gone). Nearly all rads have water traps (Mouat) not steam traps (one has just a corner elbow pipe LOL).

Upstairs rooms get too hot (likely due to modern replacement windows upstairs where downstairs are original single pane). I can fiddle with different size openings in orifice plates or just start replacing valves with TRVs (leaving the orifice plates in place) and achieve a a comfortable controlled temperature.

I am looking at Danfoss valves
(I have not found others but please suggest any alternatives) and TRVs (would consider any brand if they work/fit with the valve).

Danfoss RA2000 valves (specifically 013G8018 3/4" side mount) come with the adjustable packing gland and a grey cap that "The grey protection cap is used to manually adjust the flow. Remove the cap prior to installing an operator".
This sounds to me like the valve can operate as a manual metered valve even without add the Danfoss Manual setting knob (i.e. 013G5002).
Does anyone have experience with this Grey Cap?

It appears there are several TRV heads out there that will fit the Danfoss valve. Oventrop Uni XD for example (looks like can be had for about $45 total on Ebay). There also appear to be multiple heads on Amazon that list an "RA Adaptor". Of course Amazon heads are from China/Asia and my not be reliable but considering the $65+ cost of Danfoss heads and the number of radiators I might consider trying one or two (especially the wifi kind even though I might be changing those every couple years when they break).
Does anyone have feedback on using non-Danfoss TRV heads on the Danfoss valve?

Thanks for taking the time to read.