I also had the same issue that the Vbox doesn't get any EPG data from freesat - usually only the data for the current program.
I use xmltv from Atlas to get around this, and although it takes a fair bit of setting up initially, it works quite nicely and I have 2 weeks of EPG Data :-)
XMLTV has entries for around 90% of the freesat channels - though the ones it doesn't have entries for are quite obscure channels that I would never watch anyway.
Once you've setup XMLTV and have your .xml file, then you simply point to this file in the "EPG" section of the add-on settings and the rest should just work.
I did have a problem initially that the PVRManager would take about 5 minutes to startup when switching on kodi, because it couldn't download icons for the channels that aren't in the XMLTV file. My debug log was littered with several occurrences of the following errors:
ERROR: CCurlFile::Exists - Failed: Timeout was reached(28) for
http://192.168.0.166:55555/images/tv_icon.jpg
and
ERROR: CCurlFile::Exists - Failed: Timeout was reached(28) for
http://192.168.0.166:55555/images/radio_icon.jpg
It seems that kodi tries to establish several concurrent connections to port 55555 of the vbox to download this same icon (one for each channel not located in the XMLTV file). Since this is the channel icon URL that comes back from the vbox API (i.e. from
http://192.168.0.166:80/cgi-bin/HttpCont...astChannel).
However, it seems the VBox PNP port only accepts a couple of concurrent connections at once, so the port soon becomes tied up. I found this easy to reproduce, and in the end I made a minor code change (basically so that it discards the icon from the vbox api) and then built my own version of the addon. Following this, my kodi now downloads the channel list on startup within a matter of seconds, rather than me waiting 5 minutes before I can actually watch TV :-)
Not sure if others have encountered this problem, but it seems easy to reproduce - just ensure you have some channels that aren't included in the XMLTV file, switch on debug logging, and start the PVRManager. I'm happy to share my code change or submit a pull request if anyone is interested.