Hidden Menu for access to DiSEqC and other Satellites, yes. And you can access non-Freesat mode for 28E only without all that palaver (after carrying out a Manual Tune on 28E, the non-Freesat switch will become available to you).
True PVR functions other than for 28E, or for 28E Channels "off EPG", no. It is not a high priority for Humax to get full recording functionality on other Satellites, but it is on their list of "things to do".
But you should be able to record the "off EPG" 28E Channels and Channels from other Satellites in as crude a way as those (like me) who don't have a PVR do. ie Set your own timers etc. - Personally, I don't find it a trial!