Larry Jaques wrote:

....
The only part I can see being stressed by having a larger motor would
be the lower wheel (major) and its bearing (minor). Startup might be
quicker, creating higher initial (and inertial) stress, and it would
be able to do more work when making heavy cuts while resawing. The
upper wheel and frame are merely used as guides for the band.

I just don't buy that C-frame flex thing at all. Wider bands and the
higher tension needed to run them would be the only cause of frame
stress that I can see. No, I take that back. The frame may have more
stress AT the lower wheel bearing mount during heavy cuts. The wheel
being slightly deflected upward up would also result in lower tension
on the blade, with the tension spring attempting to take up that
slack.

You've got it except you're overlooking the fact that the blade is
pulling on the outside of the upper wheel which is applying torque to
the frame...as the motor applies more power to the blade this gets
transferred to a higher load which could in extreme case, cause the
support to fail...