I'm not sure I understand, testing codes, both neuro and psych, are time based, so there is really no problem with capturing that time as one would with therapy. It would seem that the real issue here is a grossly unacceptable time frame from the testing until the report is written and billing dropped. In most settings, you'd get about two weeks from the testing date to drop the billing, in some, just a week. In my VA time, we had two weeks for reports for the most part.
It sounds like there is no real assessment leadership to advocate for it at your location. Plenty of literature regarding the utility and potential cost savings with the utilization of testing. So, sounds like there needs to be someone to step up to the plate to go to bat for testing, you all just take what they tell you, or you vote with your feet.