I’d probably wait until I had the frame in my hands.

A steerer too long is better than too short, but a millimetre or two short is usually OK, you just need to make sure the lock nut has engaged enough threads.

You can always add a spacer if your steerer is too long, or even cut it down if it’s more than a few millimetres. If it’s wildly too long, you’ll need to make sure you’ve got enough thread for the top race.

Another thing to check is if the VO headset has a keyed washer, and if the steerer tube has a slot for one. You can always file off the tab if there isn’t a slot in the steerer, but still something to consider.