I find myself using it almost constantly, it finally allows me to work
with the early stages of virtual machine setup without getting someone
to help. And no, I don't find the ins+space to be hard at all, even
on a laptop. If you are on a laptop, you might want to try the laptop
keyboard layout (as far as I know the only difference is that it
substitutes caps lock as the jaws key). Actually, looking at keyboard
manager, that might not be true, a lot of the layered keystrokes use
INS explicitly instead of 'jaws'.
Also, I don't see any entry that would allow changing all of the
layered keystrokes at one pass.
You might want to contact FS support to see if there is in fact an
easy way to rebind the layered mode trigger.