Dehumidified Defrost needed?

Hey all, I’m in the middle of my drivetrain build. 6.4gen3 hemi/A833/HDK K member…etc on a 1970 Swinger.

Previous previous owner did a heater core delete and smoother over the heater core section of the firewall and core is gone. I’ll be modifying my dash panel anyways but looking at my HVAC system options.

Would really like to run a coldmaster universal heat/cool setup. But they have no defrost option. I know that some other companies have a dehumidified defrost option… car will be a fair weather only driver but it will be a driver/road trip car. It’s not beyond the possibility of having frost in the windshield some random morning somewhere….. or even a bad humid rain (god forbid) storm will need some air on the windshield to reduce condensation.

The vintage air and classic air both have dehumidified defrost options…. The coldmaster does not.

I’m thinking about either finding a cable or electronic duct valve to tie in the duct work to the defrost vents when I need heat/defrost with the coldmaster system. I’m just unsure on if the lack of dehumidified heat will make it a pointless endeavor?

Does anyone have any advice? Sorry for the long winded post! Thanks in advance.

Mike