In Singapore Airlines we have an "Advanced Training" programme for "fresh" CPLs (ex Baron) on the Learjet 45. It's high intensity work for the trainees, but excellent exposure to jet operations. Small the Learjet 45 may be, but so far as is practical, all operational procedures are in line with their next aircraft, the B777.
It's an expensive, non revenue operation, but has wads of savings at the B777 stage, where the training resources (staff and time) are reduced enormously, justifying the programme.
(Unusual airline SIA, operating aircraft from the Learjet 45 through to the A380).
Regards,
Old Smokey