Yeah, I've got a tendency to be blunt I'm afraid. I'm not sure how much help I can be. I am a programmer and even wrote my own channel scanner so I could add LCNs to VDR and MythTV (I originally had more ambitious plans) without having to assign each number manually, but I don't have experience of web app development focused on the server, or tvheadend's code base.
I used to use VDR for years, but it didn't support remote clients well, and never had a credible playback client unless your DVB card had its own playback hardware. I've also tried MythTV, but I think tvheadend has a better core design. Putting all the setup in a web interface is a great idea, and if you think I've been hard on it, you should see what I think of mythtv-setup!
I have to say tvheadend's developers have done a great job of figuring out how Freesat manages LCNs, but they have missed a trick. Freesat's BAT is duplicated on every transport stream, so you only need to connect to one to get the entire list of channels. My scanner takes seconds instead of minutes.