There are a couple of hills in the areas that I ride which literally put me to the brink of O2 starvation. Yes I could train more but.... I was considering changing the cassette from my current 11/28 to a 11/32 (leaving the crank set the same). I have a compact crank set at 50/34.

Are there any mechanical considerations that need to be taken care of when moving to a larger cassette e.g. like derailleur cage length etc? Or is it a simple plug and play of a new cassette? I currently have an Ultegra 6800 group on the bike.

Will moving to 11/32 make much difference climbing the hill?

Thanks in advance.