This could be a good (expensive) tool...or not. Depends how it is implemented.

If it's like the ETD and it's plagued by false positives (likely due to poor TSO technique/poor machine maintenance) that are the signal for TSOs to immediately assume the worst and trigger LEOs, backroom strip searches, etc., instead of carefully controlled re-testing (glove change/test new gloves on machine/swab/re-test pax) then it won't be a good thing at all.

I also would be very surprised if it is used for anything but testing already allowed (supposedly, depending on the whim of the TSO) LGAs - medical LGAs and infant formula/breast milk.