XX-23 S-thread tracers (card rules):
...each friendly ship at Range 1-2 of you may acquire a target lock on the defender...
Acquire a target lock (rules reference):
...to acquire a target lock on an enemy ship at Range 1-3...
If you're within range 1-2 of a ship that's just fired thread tracers, you get the opportunity to acquire a target lock.
'Acquiring the target lock' as a step includes a specific check whether you're within range 1-3 of the ship you're acquiring the target lock on.
So if you're at range 1 of the firer, but range 4 of the target, you get a free opportunity to acquire a target lock, but will fail to do so as you're out of range to target lock (unless you have Long Range Scanners, Sensor Team,
ST-321, or some similar ability)