Tim, on two occasions on two different bikes from different eras I have changed grannies down 4 teeth with no issues.
First was from 28 to 24, DT shifters, friction front. No issues, no adjustments required. 1991

2013 or 14, Around three four years ago, on a sti brifter bike, 30 granny to 26t, no issues, no fd adjustment, great tiagra sti shifting as always.

Yes on chain catcher, although the sutra may have one.
Dropping the chain generally is a fd limit screw issue, but certainly can happen with a bigger tooth difference. Catchers are about 10 bucks, totally worth getting. Chain suck is not about dropping chain, it's when you back pedal and the chain sticks to the chain Ring a bit.