Variant Drift Speed

[onatbas 10]

I like to set my drift speed to 4 as it fits my writing speed. However, the inconsistency of the drifting speed is causing me all the trouble. I cannot keep track of the writing because of the varying drift speed. It sometimes slows down, sometimes gets superfast. I don't know if that's a glitch or not, but it's hard to manage. I'd like an option to set the drift speed to a fixed value. No smoothing between speeds , just constant drift, with no variance. 

See the attachment below. All I did was to moe my pen up and down in constant speed, notice how the lines get thicker and thicker as page goes to right.