Originally Posted by operator
You can't put spacers on it if the threads don't extend low enough. Make sure there's enough threads to do this before you buy the fork. Having some shop extend threads is an exercise in frustration.
Of course you can use spacers. You install them above the upper headset race and below the lock nut to get the proper thread engagement when you install the lock nut. It's done all the time.
I agree that extending the threads is difficult and should be avoided.
BTW, the 43 mm rake will make the steering slightly slower, not "more squirrely". Less rake means more trail which is the determiner of steering response.