I never thought the condensation hood through, or had researced to that degree when tapping trees years ago, (this is well beyond traditional syrup country), but I totally buy the logic of the approach, I can see how it significantly boosts efficiency.
I will cast my vote for adding a hood. Based on my work experience, i would order up a sheet of painted (white), or stainless, flashing material from a place that sells roofing and cladding, hopefully the local hardware store. Sheet metal, especially without bends, should be surprisingly cheap.
Wish I was the one so prepared for tapping, and with the freedom of time to do it.