Thanks for sharing your "journey". I've just borrowed a 4th gen DUO to have a play with (in exchange for my spare Hummy), so it's good to get an idea of what to look out for (there may be questions coming your way if you don't mind ).
In terms of the software I've been working on it to keep improving it. The latest version I'm testing is now using TCP rather than UDP from the HDHomeRun, this stops issues with packet loss on busier networks or when Wi-Fi is in the mix. This packet loss looks just like Freeview interference so if seen tends to be blamed on the tuners and/or reception issues or the tuners not being as good as other kit. So far using TCP with many hours of recordings I've not seen a single error in any transport stream, this wasn't the case with UDP.
I'm going to get the software packaged up in an installer to make it easier to install when I get chance.