I use Tilt hydrometers and SG is tracked in Brewfather. Every brew reaches the expected FG. However, there is still some slow fermentation activity for a few days to a week after reaching FG, resulting in a lower FG than anticipated, and thus a higher ABV. My usual process is to wait until there is no change in gravity for 2 or 3 days. I am not in a hurry to keg, and I don’t have a reason to keg at FG. My beers are usually a few gravity points lower than anticipated, but I haven’t been able to say that any have been too dry or have any other negative character due to the lower FG and higher ABV. This occurs with all of the yeasts that I use and all of the beer styles.
Example: I currently have a beer in a fermenter that has an expected FG of 1.011 which was reached on Friday, then was 1.010 on Saturday, 1.009 on Sunday, 1.008 on Monday, 1.007 today (Tuesday) and is slowing down. I anticipate that it will stop at 1.007 or 1.006.
Can I keg at FG, or should I wait until there is no change in gravity for several days to ensure that fermentation is complete, off-flavors have been cleaned up, the beer has dropped clear, etc.?
Do not rely on expected FG; the yeast stops when it is ready not when a calculation says it is done. Expected FG is just a rough estimate that doesn’t take into account how you brew and your brew system.
I don’t think Bf is intentionally conservative. It seems to use about the midpoint of the expected attention stated by the yeast lab updated with some estimates on the fermentability of your wort based on the mash profile. If you notice a predicted value is consistently off from your actuals, check through the model parameters and can probably find which one to tweak to correct for it.
You could try to update Brewfather so you get a better estimate of the FG for recipe formulation purposes, but I still would not rely on the expected FG for determining when fermentation is over.