I have been routinely fermenting under pressure lately - usually around 10 psi and I brew mostly lagers. I know people say that the warm fermentations speed up the fermentation, but over the last year or so, I have fermented my lagers cold - at or near the middle of the yeast's recommended fermentation temperature. This has been in the 50's F. The lagers still finish fermenting quickly (4-5 days) at the cold temperatures. This is purely anecdotal, but I wonder if the pressure, itself, speeds the process.
I use a Tilt hydrometer to measure the progress and don't rely on it as to an absolute in terms of FG. I am often able to rack to a serving keg at the 4-5 day mark (under CO2) and lager in the keg for a couple weeks before serving bright, clear beer.
Just wondering if anyone has similar or different experiences with cold fermenting under pressure...