Are you asking to build an interface that rivals Material (which won't happen) or to just surface the LMS library?
Assuming it's the latter then you need to ask LMS to improve its UPnP plugin, there's nothing WiiM can do about it (unless they build a smb browser).
If you really want a UPnP interface to your music, then install a UPnP server alongside LMS (on a different Pi).
All of this is alphabet soup to me. In a previous post I said the WiiM stuff works great (device and app). I also seen that the track skipping issue happened on both the Material and Orange Squeeze app, so I doubted it was the app, but am guessing LMS or the plugin.
I really don't understand a lot of how this all works, but I got to see a better app experience with photos, band info, album info, and lyrics. I never thought WiiM was responsible to add any of this. I was told LMS and Material could do that (with plugins). It does but it is buggy.
It turns out that (AFAIK) that there are 2 UPnP plugins will make LMS mostly compatible. One plugin lets LMS cast to our WiiMs, the other lets WiiM Home App see the LMS library. I was told one of the plugins is no longer supported and that I shouldn't use it.
As it is now, the track skipping is the biggest issue for me. I am led to believe the new WiiM firmware will *probably* fix that and eliminate the need for the UPnP Bridge plugin. I hope so.
With the UPnP Media Bridge plugin the WHA now sees the LMS library. It shows song Artists instead of album Artist, but otherwise *seems to work*. If need be, I am not opposed to only using the Material app to access and play my music.
I don't expect WiiM to do anything. Their device and app work. The WiiM/LMS/Material combo is REALLY nice. I hope the upcoming firmware update fixes the track skipping issue with WiiM/LMS. If not, I hope someone works on one or both of those 2 plugins.
I am a novice and may be way off base on all of this. I just wanted to share what I see and hope someone can make WiiM/LMS work better together.
Thanks!