My "thought" is that the small-framed compacts are to light for this setup. I think it's has a lot do do with the fact that the plow is just to far out in front.
My plow was 60" wide, my tractor wheel's are 48" wide, when the plow was angled (30*) it only cut about a 52" swath, so the blade was not oversized for the machine...
Just by shear geometry, when the blade meets restistance and the tractor continues to push forward, the front of the tractor gets lighter and all steering is lost except for indendent brake steering which is helpfull but will not overcome the snow pushing the blade to the right or left depending on which way it's angled.
The blade I made was very similar to the Curtis setup and the one that JD sells for the loaders on the mid-framed CUT's.
Another thing to consider is the overall length of the machine with the FEL plow and rear wieght, it can be very cumbersome in smaller parking area's and driveways.
DISCLAIMER: These are just my experiance's with my setup, and a few other's I have talked to with simular setup's, one was with a JD4310 and the Fronteir (JD) blade,