A long time ago, I used to fly a 206B-III for a certain 3-letter small-package carrier (not UPS). The ship, based at KJFK sat out on the ramp overnight for a time before it got moved to a hangar at an airport out in the suburbs. Now, New York City isn't known for its extremely harsh and frigid winters, but it often did get damn cold in January. And sometimes, from sitting out overnight, that little B-model would be well and truly cold-soaked by the time I got to it for the morning runs. Sometimes I'd give those glow-plugs a little extra time to get hot, and then I'd turn the key and the starter would groan as if trying to turn over my dad's old Packard-8 with the high-compression pistons. It would usually light off, but the TOT and N1 would just stagnate somewhere around 40%. I would let it sit there - briefly! - for a moment before shutting it back down. Then I'd simply wait a bit for the heat from turbine section to soak through (out?) to the FCU. Next attempt was always fine.
The next problem were the temps. Engine oil temperature would come up quickly as you'd expect, but the stupid transmission temp...man, with no load on the trans, you could sit at idle for a loooooooong time before the trans temp would even start to get warm. What I ended up doing was bumping the N1 up to 70% or so and then pulling some collective. Worked like a cham and the trans temp would get up into the green.
Sometimes the RFM's don't cover every situation and eventuality that we dumb pilots find ourselves in.