When I moved to the US I needed to resurrect my FAA ATP that had been gathering dust. It was MEL only at the time but I figured at some point while living & working here I'd need or want to use a single. I'd always wanted to do a seaplane rating so I did a combined ATP-SEL & SES in a C180 amphib at Flagler County Airport in Florida. Close enough to home to drive there each day so convenient too.
Never having done a US PPL or CPL, damned if I wanted to have to muck around with chandelles, turns around a point & pylon 8's and the like from the PTS for those licences. An ATP test is really just an IR test and I've lost count of how many of those I've done over the years. Add the floaty alightings part to the terra firma landings and we met the PTS for both SEL & SES.
The bloke got a dispensation from the FSDO to do my checkride even though he did my training. It probably helped that it wasn't an initial issue ATP.