In the Disney trilogy it is established that “light speed tracking” is thought to be impossible. That is until TLJ when it’s revealed that the First Order now have this tech and used it to track Leia and Poe.
In ANH Tarkin has a homing beacon planted on the Falcon to track them … through hyper space. Homing beacons are also used in the prequels, at least once.
What is the difference between light speed tracking and a homing beacon? Is there a difference between light speed and hyperspace?
The short answer is lightspeed tracking doesn’t need anything extra to track a ship through hyperspace. As far as I’m aware, it created a static hyperspace map in a computer and was able to track ship movements through hyperspace by seeing changes in the map. Doesn’t make a lot of sense, especially when, as you have stated, there is already technology in-universe that lets you accomplish the same goal. But hey, it’s Rian Johnson, what do you expect?
The main difference is that with this computer, you can track any ship you want without the need of placing a homing beacon on it first, so you can track any number of ships you want whenever you want to. Also, some ships have scanners to check for things attached like homing beacons. This type of tracking would bypass that as well.