Options for displaying HDR photos

I’ve been editing in HDR in LightRoom Classic for a year or two.  I create collections and sync them.

When I open these collections with HDR photos in the Lightroom app on my M4 iPad Pro, these image look terrific, the highlights pop, bright and vivid.

But when I play a slideshow of these collections, the photos aren’t in HDR like when I open these collections photos manually.

Either in slideshow mode, they open SDR versions or maybe the slide show transitions too fast for the HDR metadata to be rendered?

When I open them manually it takes a second or two for the HDR effect to load for each file.

Beyond editing and viewing HDR photos in LightRoom Classic or the app on devices with HDR displays (or what Apple calls XDR displays), what other software can display HDR properly? 
 

I’m enticed by the Studio Display XDR which Apple just shipped.  But hard to justify that price unless I can display HDR content as slideshows, screensavers, wallpaper, etc.