It only makes sense that the sensors will be "under the table" and at the cashier, because the range of the chips, in the chips, is not that great.

Unless they install loops like we walk through in the retail stores, to exit, the new chips will be able to come and go.

Just imagine people staying at the hotel? Would everyone have to cash out, to go to lunch next door? Not an issue.

However the roulette question would make some sense if it registered every chip on the table and kept count. "Chip down, HEY a roulette chip is missing!" Alarms and security come running, only to find it on the servers tip tray.