You want the stem's quill expander to be below the threads in the steerer so you don't want the steerer so long the stem doesn't clear the threads. However, some steerers are butted and thicker walled toward the bottom. Your Technomic should work if it's not so far down that it hits any butted section. You can use spacers between the top race of the headset and the locknut with that caveat in mind.