The problem for the TPG might be not so much trying to keep the population figures accurate (which would be nice), but perhaps folks would be less likely to submit the coins for regrading. In theory each is a new grading event, but if there is 'recognition software' I'm sure quite a few people would suspect that incoming coins would be run through the process prior to grading (once set up, perhaps a fairly automated process) and the old grade would be spit out automatically. That might cut down on the crack out crowd, and thus cut down on grading fees. Spending money to lose money may not be a thing the TPG would go for. I don't know if such an automated process would be both effective and cost effective at any point, but people might fear it could be so.