VPP support for XR24

I'm encountering an issue when attempting to import a DMA-BUF with format XR24/BGRX (0x34325258) and modifier I915_FORMAT_MOD_Y_TILED_CCS (0x0100000000000004) using VA-API.

When calling vaCreateSurfaces() to import this DMA-BUF for use with VPP, the function fails with the error: "the requested RT Format is not supported".

This is unexpected because when I query the supported formats using vaQuerySurfaceAttributes() with VAProfileNone and VAEntrypointVideoProc, XR24/BGRX and similar RGB formats are explicitly listed in the supported formats:

- Format: NV12 (0x3231564e)
- Format: I420 (0x30323449)
- Format: YV12 (0x32315659)
- Format: YUY2 (0x32595559)
- Format: 422H (0x48323234)
- Format: 422V (0x56323234)
- Format: RGBA (0x41424752)
- Format: BGRA (0x41524742)
- Format: RGBP (0x50424752)
- **Format: RGBX (0x58424752)** Maybe its not the same as XR24?
- Format: P010 (0x30313050)
- Format: RG24 (0x34324752)
- Format: ARGB (0x42475241)
- Format: ABGR (0x52474241)
- Format: AR30 (0x30335241)
- Format: AB30 (0x30334241)
- Format: XR30 (0x30335258)
- Format: XB30 (0x30334258)
- Format: AYUV (0x56555941)
- Format: Y210 (0x30313259)
- Format: Y410 (0x30313459)
- Format: P012 (0x32313050)
- Format: Y212 (0x32313259)
- Format: Y412 (0x32313459)
- Format: XYUV (0x56555958)

Environment
Intel(R) HD Graphics 530 (SKL GT2)
GPU device: /dev/dri/renderD128
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
VA-API initialized (version 1.23)

Is there a different way to specify the XR24/BGRX format for DMA-BUF import that would work?
Are there specific restrictions on which modifiers are supported for which formats?