If you're pitching 34/70 at 69 degrees then this thread might be the safest place for you
Any time I ever underpitched 34/70 the biggest problem I had was it stopping short. Sometimes really, really short. I have never used Go Ferm, though, so hopefully that helps. Maybe move it to the 68F room for the last few points or so to give the yeast a better chance of finishing the job. It shouldn't hurt the fermentation profile at that point.
Honestly, if I were you a day ago I would have just stuck it in the 68F room to see how it turns out. You likely would have still gotten a pretty drinkable beer. If it's stable in the utility room now and still dropping in gravity then I'd vote just leave it there and then move it to the 68F room for the last 10 points or so.
For future brews, if you can push the wort down to around 58 or a little lower and then do the majority of the fermentation in your utility room at 58F ambient then you'll get a pretty clean beer out of it. Even a little warmer should be fine. I also know some brewers around me pitch warm and let it chill overnight in the fermentor. My only other advice beyond that is just pitch plenty of healthy yeast. That's the biggest problem I've ever had with 34/70. Welcome to the warm lager club, and the lager club in general,
@z-bob!