Slackware 15 seems to have pulseaudio 15 so should be able to do sony's ldac bluetooth audio format, but pulseaudio needs gstreamer 1.20 and specifically the bad plugins to work, and slackware 15 is on 1.18. So I was going to build gstreamer and the plugins for 1.20, but I also noticed slackware breaks up the bad plugins, and supplies the free ones but not the non-free.

My question is does Slackware current, which has gstreamer 1.24, have the ldac codec in the gst-plugins-bad-free? and could I just use these SlackBuild scripts from current to build gstreamer 1.24 for Slackware 15 and get the ldac codec this way?

Looking through the Slackware current ChangeLog I don't see anything that reads like "Recompiled for gstreamer". I guess you would be okay with the newer gstreamer. You could go back anyway to the old version.