If a Security player have to choose between a test that require a second party, aka the Chaplain that is off doing their own stuff, to do the test for them. Or a test that they can do themselves and takes around 60 seconds. They will most likely do the latter.
If we had a option, like the body scanner that the brig phys often get installed, to scan the suspect I believe the Security player would choose to that before chugging 40 units of holy water down the, (mabye) not confirmed, cultist throat.
And thus eliminating (some) wrongful testing.
This might make the Security processing in a Cult round a bit too easy though.