If you fit a shorter stem, the easy way to overcome the wanderyness on the climbs (most people forget to do this) is just bend your elbows loads, and lean forwards…
Anyway… Stem length is a real horses for courses thing. What suits one person, may not suit another. And what suits one bike, will not suit another! On one of my bikes, I’ve just swapped back to a 90mm stem from a 70mm cos with the 70mm on it, it felt too relaxed and lazy! Conversely with the 90mm on, the bike seems to rail into corners and generally feels a lot more eager. This is probably more to do with where my weight is on the bike (lower and further forward with the 90) than anything else, but to me the difference is like night and day!
Conversely, an old bike of mine felt horrid with a 75mm stem on, as soon as I put a 50mm stem on it, it transformed the handling!