Since when did Linux-native REAPER start working? It's certainly not finished but you can already record with the native Linux version of REAPER.
The main issue as it stands is that it seems you are restricted to the plugins that are bundled with REAPER, or at least I have had no success in getting it to recognise the U-he Linux VSTs I have installed. The font rendering needs some love and the file dialogues aren't working properly but JACK IO is working and I have successfully recorded, saved and loaded a small test session with a few FX and played around with the MIDI editor a bit. Native Linux REAPER is most of the way to being a usable reality, all it needs now is a talented, interested coder to add the finishing touches to WDL as Linux would seem to be something COCKOS are willing to support but not prioritise, yet.
It only took me a minute to install REAPER from the AUR but take note of the editing required to the PKGBUILD mentioned in the only comment on its AUR page.https://aur.archlinux.org/packages/reaper/http://www.landoleet.org/dev/
The latest Reaper Linux version (5.29) seems pretty stable to me.
It does do vst's but with just a basic UI, so there are no visual buttons or knobs and just mainly basic sliders and things like kit loading into Drumgizmo won't work or loading presets into u-he won't work because there are no buttons appearing to actually enable it.
But there are some workarounds.
I've had the u-he vst's running but the h2p preset files (u-he's own cross platform preset format) can't be loaded (no plugin gui) but fxp preset files can be loaded via Reaper, so the h2p presets need to be saved to fxp format (u-he seems to name these native preset files) using the u-he vst's in another host like Ardour or Tracktion etc and then the saved fxp presets need to be copied out of u-he's hidden diectory (home/username/.u-he) so that Reaper can see them as Reaper doesn't seem to be able to see hidden directories.
After all of that, the u-he presets work as expected in Reaper.
There are some u-he fxp presets floating around on the net already such as Retrohead for Triplecheese https://www.u-he.com/PatchLib/tc.html
and Factory Remix for Zebra http://u-he.com/PatchLib/zebra.html
and Magnetic for Podolski https://www.u-he.com/PatchLib/podolski.html
Reaper Linux can load vst fxp/fxb preset files for a Linux vst plugin.
(save as fxb = saves all presets in the current plugin.
save as fxp = saves the current preset only)
I've also had the Drumgizmo vst running in Reaper Linux but the file loading buttons (Browse buttons) don't appear on the basic vst UI, so I modded the Drumgizmo code to autoload the kits and it all works very well.
Another way is to use Carla or Jost (I had to modify the Jost mutichannel code) as a vst host and load the Drumgizmo vst into it and then connect the outputs to Reaper ins using QJackCtl etc.
(The Drumgizmo vst needs to be compiled from the latest sources to get around a JUCE bug that stopped the Drumgizmo browse buttons working in Tracktion and Jost etc).
Reaper Linux can have multiple ins and outs appearing as Jack in and out connections, so connecting a multi channel host (hosting multichannel Drumgizmo) up to Reapers track inputs isn't that hard, and then each track in Reaper can have it's own vst effects, like for example the Drumgizmo snare track can have effects placed on it inside Reaper.
Sending a midi file in Reaper (track 1) to Drumgizmo loaded into Jost and then receiving the Drumgizmo audio channels (I only connected 4 channels up for the test) back into Reaper on tracks 2,3, 4 and 5.
Connecting the Jost output channels to Reaper inputs.
Connecting for monitoring in Reaper.
Connecting Reaper midi out to Jost midi in.
Drumgizmo channel connection in Jost.
Playing the track 1 midi file and recieving Drumgizmo drum channels on tracks 2,3,4 and 5.