Goofs

In order to remove the inhibitor chips using the Jedi cruiser's med lab, Tech builds a separate brain scanning device to compare the Bad Batch's brains to Rex's (as Rex has already had his chip removed). When Ahsoka removed Rex's chip, she did so using only the equipment found in the cruiser's medical bay. No separate scanning device was required.

Ahsoka used the Force to locate Rex's brain chip. The Bad Batch needed to find the differences in their chipped brains and Rex's unchipped brain to see their own chips.