To perhaps give a few clues as to what distinguishes these graphite Steinbergers and the copies:
There is first what you might call a 'real first thing'. A full graphite Steinberger L, or XL bass. The 'original Steinberger', so to speak. This is the benchmark, a real milestone, both in terms of design, ergonomics and especially sound.
Then there are three variants that can also be called 'the real thing': XP, XM and XQ. They all consist of a bolt on graphite neck, in the 'Steinberger Blend', in combination with a maple body (because of the high density with outstanding overtones).
Then there are lots of wood copies. From Hohner, Cort, Washburn, ...., and last but not least as Steinberger Spirits.
Basically you can say: nothing comes close to the 'real things'. No matter how much you modify. That's just the way it is, it's physics.
If you want to get in the direction of a real Steinberger with an all wooden bass, you should note: a bolt on neck and active EMG HB pickups at the correct positions are important.
The neck thru wood basses have quite good sustain, but you can forget about the attack. It never sounds like a real Steinberger.
And since the passive XPs, there aren't any pickups that come close to active EMGs. Those passive EMGs on the XPs have been specifically designed to come as close as possible to the active ones. Which they do very well, but not 100%.
Of the XP, XM and XQ, in my humble opinion, the XPs with active HBs are the closest to the XL models. But you can look at it another way and not to forget, Steinberger has always made subtle changes within the series.
As always, YMMV
