Alternatively, to solve my issue I could simply remove the evdev configuration file from /etc/X11/xorg.conf.d, but then I'd like to somehow change the default input driver for any mouse from libinput to evdev - and I can't seen to find a way to do that yet.
The whole original goal of moving away from the libinput driver for all of this was to completely disable pointer acceleration, after reading on some post here that libinput did not support truly flat acceleration profiles and only had a half-arsed implementation of them. I would also be fine with using evdev as my touchpad driver, if it were not for the lack of features such as 2-finger scrolling, edge scrolling, among others that Synaptics brings.