Kodi shouldn’t be crashing but if you turn passthrough on for TrueHD (change your settings view to expert) the crashing will probably stop. On an unrelated note I would recommend changing your display resolution…
We recommend people with 4K TV’s set their user interface (UI) to 1080p. Kodi’s UI is not optimized for 4K yet and this can put unnecessary demands on your device and can lead to a suboptimal picture quality, as well as potentially cause other issues.
With the above settings your UI will be output in Full HD and your 4K content will be output in 4K. *Information regarding the whitelist can be found here. If you have any doubt, feel free to upload some logs so we can verify that your settings are indeed correct.
The passthrough options are not new, but you do have to switch to one of the more advanced views to see them. As for the resolution it affects both the UI and videos, but when you enable refresh rate switching that allows for videos to be played at higher resolutions. If your really curious you can click on that link at the bottom of the suggestions for whitelist info and that will probably give a fairly good understanding of how it works, even when your not using a whitelist.