I've noticed a few interesting things about the pre-engineered FSD v1 - it's not the best solution for every ship, every build, or every situation. It needs more power and produces more heat. I have 6 of them - and sometimes I come to the conclusion that 5 would be quite enough for me.
For any build that wants to stay as cool as possible, v1 FSD should be avoided. For example, to sniff around the Titan, I use a 5A FSD shielded/thermal spread.
I also noticed that even when the temperature of the ship is not particularly important, that FSD v1 provides almost no benefit. For example, I take some missions to kill pirates, about 10 - 20 LY around some system - and I see that v1 FSD does not bring me any advantages, because in such situations I usually don't care if I have, for example, 22 or 25 LY jump. Or if I need to travel 40 LY away - again that difference in range is irrelevant to me, as I need two jumps no matter which FSD I use.
And of course, there are instances when FSD v1 is really useful - for long trips with DBX or ASPX or Phantom.
What I'm actually saying is that the usefulness of that module is limited.