Mouse sensitivity and how annoying it is to change

Why is that mouse sensitivity has to be changed in increments of 5. Until recently I enjoyed playing at in game sens 45. But recently I noticed extremely shaky movement so I bumped it down to 40. And that was way too slow. I did some research and found out you could change the config file of league gamemousespeed to a fraction of a number. How it works is like so.

GameMouseSpeed=1 --> 5 in game GameMouseSpeed=2 --> 10 in game GameMouseSpeed=3 --> 15 in game GameMouseSpeed=4 --> 20 in game GameMouseSpeed=5 --> 25 in game

You can change the in game config file to 4.5 which would grant you 22.5 sensitivity. Or so I thought, when I change this setting in the config file and play league, its as if I changed nothing in the config file. After changing the config file I don't fiddle with the slider anymore or anything I just go into a bot game to test it out and it just remains the same. I need to somehow make my sens just a tad bit faster or slower for LEAGUE ONLY and change my in game sens to 40 or 45. Its so ridiculous that they don't have mouse sensitivity in increments of 1. Way to limit the customization of game options.