Don’t hand passport to a third party is safest option, immigration have controls in place and you get a receipt when you leave it for visa renewal. It’s just overnight anyway.
It’s an issue related to the change in payment process, pension used to be collected from the post office every week, always remember my Nan doing it, with auto payments now they have to avoid all the scammers out there which I fully support I wonder what age this kicks in, bit of a pain for us living offshore……
they have tightened up since exemptions were introduced, I know many folks who have been challenged incl my wife who made two trips back to SIN(her home) whilst renewing her retirement visa, both times she was questioned regarding her intentions - after explaining she was admitted - not sensible to encourage people to game the system can have serious and expensive consequences but ETA will put an end to all these debates thankfully.
The fact that you have already had a retirement visa will be a red flag you have already demonstrated that you are not a genuine tourist, first time you will be questioned about your intentions thereafter you may be denied entry or at least given a final warning and flagged on system……better to just legitimize your status,