Couple Questions about Kodi 21 and Flatpak

I have been a long time user of Kodi, but I have always installed through the PPA for Linux.  But I see that now you are using Flatpak, I have never installed or used a Flatpak so I know nothing about them.  But my big question is I have always used a line to start Kodi that uses ALSA audio, is this still possible with the Flatpak version and if so can you tell me how?  Also I am wondering if under Ubuntu 24.04 using the new Kodi 21 Flatpak, can you do HDR now for 4K content?