That’s very helpful thanks. I could see a scenario where the customs officials could do a 100% stop on passengers as they have the data linked to the passport. Good to hear it is more practicable than that.
I got quite confused about the process at the buying point. As you say, some shops seem to send you to their tax-free counter where they hand you back a refund in cash (sometimes after deducting a handling fee) but others seem to be charging me the tax-free price (again sometimes with a handling fee deducted) at the point of purchase. And one store (Itoya) sealed everything into plastic bags because my purchase included a bottle of ink and this counts as a consumable, although they also sealed up a second purchase which was just a pen stand, so I think they don’t fully understand the new process either!
I actually used the automated system when exiting and never spoke to anyone from customs.
To be fair, they never verified anything on departure with the old process either but the piling of receipts in your passport was rather annoying so I see this as an improvement.