I realize that $330 or so is very expensive for a modification
of a planer that you already have that same amount (or more
as in my case) invested in the tool itelf.
I like the spiral better that the straight cutter type in that it is
always removing foam and if I go really fast I don’t get “chatter”
marks on the blank. They also seem to cut better on the
back pass (to remove bumps).
You shouldn’t have to worry about voltage, most house current
or garage current will vary from 110v to higher anyway. Amperage
is more important in that is what is measured in terms of the amount
of work a motor can do.
I have not had a problem with either my Skil or my Hitachi heating
up with a spiral bit and an exhaust system even on full cuts on large
stringers.
I would follow the advice and not use it for balsa boards. I have
only shaped a couple and have used my blade Hitachi on both (carbide).
I think that my spirals should last my backyard career and eliminate
all the time I used to spend in adjusting/replacing blades.