NB! It seems this console command is not compatible with CS2.
Command Profile

M_CUSTOMACCEL_SCALE

CS:GO

This is the command that determines what the value is for the custom mouse acceleration command. The higher this is, the faster your mouse acceleration will be.

Syntax
m_customaccel_scale [Scale]

Description

This is the command that determines what the value is for the custom mouse acceleration command. The higher this is, the faster your mouse acceleration will be.

Syntax And Arguments

m_customaccel_scale [Scale]
Scale How high or low you want your mouse acceleration to be. The default value for this command is 0.04.