I'm sure other people have discovered this already, but it's something I only realised today. Having never bothered with the faster boot modification, it occurred to me that when I'm mission running in a small network of systems, jump range is not important. So, I thought that instead of engineering for range, I'd see if I could speed the jump sequence up - surely that's what the faster boot modifcation does, yes? 
Turns out that faster boot is literally that. If you turn your FSD off, the time taken for it to be active from when it is turned on again is the boot time. I don't remember the last time I turned my FSD off (besides today, purely to test the theory) - why on earth is it an advantage to have it boot in 2 seconds instead of 10?! I can think of one in-game situation only where it could be useful - presumably when you've had the drive disabled by an enemy and you can get them back online more quickly.
Are there any situations where this modification is useful, or is it really the dud it seems to be?
Turns out that faster boot is literally that. If you turn your FSD off, the time taken for it to be active from when it is turned on again is the boot time. I don't remember the last time I turned my FSD off (besides today, purely to test the theory) - why on earth is it an advantage to have it boot in 2 seconds instead of 10?! I can think of one in-game situation only where it could be useful - presumably when you've had the drive disabled by an enemy and you can get them back online more quickly.
Are there any situations where this modification is useful, or is it really the dud it seems to be?