Steps to reproduce:
1. Open the attached user's project "Xr Cam Performance Hell.zip"
2. Connect Quest 2 to Oculus Link
3. Make sure "Default OpenXR" in OpenXR provider settings is set to "SteamVR OpenXR"
4. Enter Playmode, make sure VR is working
5. Check the FPS in the Editor, it should be as high as the Headset Supports / is set to
6. Click on "Extra Cam 1" GameObject, enable the Camera Component
7. Observe the FPS again and it's reduced by half

Expected results: No editor performance drop when using SteamVR OpenXR and more than 1 camera is present
Actual results: Editor fps is reduced by half when SteamVR OpenXR is used and more than 1 camera is enabled while in Play Mode with Oculus link

Reproducible on: 2022.2.0b1, 2022.3.2f1, 2023.1.0f1, 2023.2.0a18
Not reproducible: 2021.3.27f1, 2022.2.0a16

Notes:
-Issue does not reproduce with other OpenXR runtime settings
-Issue does not reproduce with the OculusXR plugin
-Issue reproduces with Valve index
-Issue also reproduces when "Play Mode Default OpenXR" is set to System Default, however the issue on this project I could only reproduce with SteamVR OpenXR Play Mode option in OpenXR plugin