New Cabinet Over Air Register on Floor
Do the toe kick vent!
The home I was renting/am in the process of moving out of had the kitchen vent capped to run forced air to a new 3 season room directly behind it, the room furthest away from the furnace.
Result- warm air that was cool air by the time it got to the end of the run in the 3 season room, no heat in the kitchen, and thus ~15* cooler in the winter than the dining room directly next to it.
Best part- the guy that did it owns an HVAC contracting company in Grand Rapids. Nice.