crusintx, Shifting problems with the chainrings generally occur when shifting to a larger chainring rather than downshifting. Chainrub with the middle chainring may happen if using the smaller cassette gears and the granny, but you're likely not in those gears when facing a climb anyhow.

It's generally better to anticipate when to use the granny. By this I mean go to the granny and upshift the rear a couple of gears and then downshift the rear as needed.

Brad