The way to remember it is OpenVR is the new name for SteamVR, where Valve tried to make their stuff the standard and released the API spec with no patents/royalties. No-one bit (or rather Facebook/Oculus ignored it, as having designs on PC VR at the time), so it took OpenXR to be the new open standard. Pretty much the only thing to use OpenXR is MSFS. So this thing for OpenVR will work with X-Plane, IL-2 BoX, DCS, and pretty much anything WMR that uses SteamVR.
The charts and recordings are are from CapFrameX - Driver Comparison 457.30 vs 466.11 for DCS 2.7 & MSFS VR.
For a live view I just enable the Performance Graph in the SteamVR desktop app. You can right click on it and get the options. The colors and framerate timing give a good indication on how things are going (green good, yellow on the limit and reprojecting, red pauses etc.). In the developer settings of the same app you can enable the chart in VR as well if you don’t want to nose peek.
