On a different note: once TTP issued, and if not enetering via one of the above TTP-enabled POE, does it mean the Visit Japan Web App would have to be used (as if there is no TTP)? Is there any other process for travellers with TTP?
Yes, you would have to fill out VJW, but given that VJW just now just uses a single QR code, which means you only fill out a single page for both, and you still need to fill it out for customs, it shouldn't change anything from your normal process.