I tried your Pi4 build it with a spare Raspberry Pi 4B 8GB and basically everything worked. Compressed FSBS files (3840x1080) were being processed on the fly and sent as frame-packed. However, as soon as I tried larger 3D MVC rips with higher bitrates of about 42–48 Mb/s, there was severe stuttering during playback. I switched from SMB to NFS and tried various tweaks in Kodi and LibreELEC, but nothing helped. Eventually, I gave up. I think the RP4's hardware is not powerful enough. Should I try again with an RP5?
Yes, MVC is pushing Pi4. You could try overclocking (the arm) but it may not be enough.
I think Pi5 will be fine with these files.