in my mind the reason not to put a caliper inside the triangle is safety. If the bolt undoes itself - which *can happen - it can just fly away. A normally installed caliper will most likely stay put even if the bolt is loose.
i'm sure this can be made to work, and worse come to worse i can just run a forward facing brake, won't be the first time i've had some weirdness on a bike.
that's unfortunate.
in my mind the reason not to put a caliper inside the triangle is safety. If the bolt undoes itself - which *can happen - it can just fly away. A normally installed caliper will most likely stay put even if the bolt is loose.
the frame color looks great with tanwalls !