I had posted a while back that Buzz should program in a "channel 0 (zero)" in the Buzz TV app that was a dead channel that pointed to nowhere. That way we could launch the app, keep it up all day but as long as it sat on channel 0 no bandwidth would be used. Most people in this group thought that was a stupid idea....whatever.
I currently don't have a sub as it ran out and I wont re-sub until winter so I am working from pure memory here. I had a work around for the exact issue you speak of. Since the timer will not launch the Buzz TV app, or even turn on the Buzz box, you have to leave the box on, and the app open. Now I don't know (since I no longer have a sub) if it's still there, but Papiao had a channel 999 which was listed as a "test" channel. At the time this channel was dead; didn't point to any URL. If this is still the case then you can use channel 999 for this work around.
Turn on the box, launch the Live TV and turn to the channel you want to record. set your timer via the guide (if the guide is correct), or set the timer manually. once completed turn to channel 999. If 999 is still a dead channel then you will burn no bandwidth (except for the minuscule amount of data used by the Buzz app checking for a handshake for channel 999). Now, while on channel 999 set a "reminder" via the manual timer for 5 minutes after the timer is set to end on the channel you want to record. set the reminder for channel 999.
If done right this is what should happen:
Lets say the show you want to record starts at 12:00 and ends at 13:00 on channel 100. turn on channel 999 in the morning before you leave for work....no bandwidth is used on 999. At 12:00 the timer switches to channel 100 and records for an hour stopping at 13:00. When the recording stops you'll still be on channel 100 burning bandwidth. This is where the "reminder" comes in. At 13:05 the reminder fires up and switches back to channel 999 where the Buzz app will sit for the remainder of the day burning no bandwidth until you get home.
If 999 test channel is no longer there then look for another channel that's dead. If I remember right there were a couple of dead Special Event channels that could be used. I know there were a ton of international channels that were dead, but they come and go and any ones whim so one could fire up and start streaming while you're at work.
Play with it and see what you come up with.