There may be a particular advantage to those that are more suited to chasing than hurdling. If going straight from hurdling to chasing they will be running off the equivalent of their hurdling handicap mark, so if better suited by fences it makes sense to run them in a handicap where they have an advantage.
It’s only a theory, but I would guess one trainer who does this more than most is Donald McCain jnr. He typically has more chasing types than hurdlers and it’s not unusual for his charges to make their chasing debut in a handicap. A notable recent example was Gershwinner, running off what looks in hindsight to be a generous starting chasing mark of 95 at Perth. He won with a good deal to spare and then backed up the form with a decent second off 104 under 12-2 at Cartmel next time.
Rob