I was able to start some of its private activities with ActivityLauncher as root. Most of them just crash immediately, but the help page is available. And yikes, they got them covered against a possible bypass, no developer tools or sideloading.
Still disappointed this is shipped in LineageOS, but I suspect not for much longer with that publicity.
LDAC works just fine on Linux, but may be a different package or repo since it’s somewhat proprietary. Just worked out of the box for me on Arch.