It just dawned on me there is no mounting a regular HF size radio under the dash as the downtube is in the way.
Oh, I can ditch the downtube and I guess the remaining vents would get quite intense.

That, or find another radio with a detachable head so I can mount the big lump that is the power/RF section under the seat. But I discovered the radio gets annoyingly hot under there with no airflow. My final choice I guess is mounting my non-fan VHF radio under the driver side, (I actually move my seat A LOT as I can't drive in one position for long periods) and mount my hot HF radio under the passenger seat and leave the heat outlet open.

Protip for noobs. Make sure you have adequate space for TWO normal size radios in the ride you plan to buy.