I have an original version Freya and have never worried about its warmup time and I listen to the tube section exclusively. I like the fact that it doesn't turn off the tubes when I switch to one of the passive settings as its a great way to see if the tube stage is getting tired...instantly. Also, I still haven't found any remarkably better preamp at any price (I've owned some great preamps, and compared my Freya to various other things)...to claim it isn't as good as other more expensive stuff make no sense to me...its considered Class A to many.
Tube Preamps Should Have This Feature
So it's late or you just want some casual listening for a short time. "Should I fire up my tube pre for 30 minutes?". My answer is "No". Why not let me flip a switch (or push in the volume control) to put my pre into "bypass" mode? Bypass would, effectively, convert your pre into a passive device, keeping the tubes dark.
This sounds useful to me.