Add any external sound hardware, use a optical or SPDIF port instead, add some speakers. It'll break sooner-or-later, and in my own experiences it tends to be whenever my personal computer gets away from the 'typical' desktop profile.
Pulse audio + reconnecting bluetooth speaker after it powers off = bad day
The OS is great when it works, but then those little things are always around the corner, turning weekend actions into weeks.
Also, the people who manage Linux distributions seem to absolutely love suddenly getting rid of things that work and replacing them with incomplete alternatives, without any kind of migration of user data and settings. Those alternatives should be pushed out as developer previews until they either
(1) match each and every feature of whatever they are replacing AND capable of importing all settings
OR
(2) warn the user months ahead of time with a list of features that are going to disappear in the replacement
OR
(3) provide an easy, 1-click option to let the user continue using whatever they were using as their default, with continued support and updates
But it is still my main OS everywhere, I refuse to bow to proprietary overlords. Despite these downsides.
What would have been preferable would be for the HTPC to advertise itself as a audio source, and the laptop to be able to list sources, and let the use select one.