XP1, it's been that more or less since the start of the pandemic.
We don't hand over the PDA to the customer now to limit the chances of cross-contamination. The standard procedure for signed-for items is we're supposed to put the item down, knock, step back 2m, ask the customer if they're happy for us to sign for the item, if so, enter their name and XP1 in the signature box then submit it. If they're not then we put it in as refused and take the item away for return to sender.
And yes, I do know a lot of postable signed-for stuff gets put through without knocking.
That's how our lovely postie Nigel works.
Ring the bell, stand back and self sign. No problems. I've been self signing as well since the start of it all. Enter the customer's name and sign it myself, as well as a before and after unloading photo, just in case.