I've been using the nightly H6 build for my Orange Pi 3 for a while. Every once in a while there's hiccups, but I like it quite a bit and it seems to work very well. I really only have one plugin, for MythTV. This is on a 4K TV.
Over the holiday break, I upgraded from 20200917 to 20210102 and noticed that when viewing recordings from MythTV, the video and audio would pretty quickly get out of sync. I poked around and eventually found that deinterlacing was turned on by default. After turning it off, the video stays synchronized.
I don't know if deinterlacing was turned on by default before, but if it was, it worked. If not, I would like to find where to turn it off for everything, but a search of where I thought it might be in the interface failed to yield a result.
I don't know if the deinterlacing synchronization issue is a bug I should report somewhere?