This problem was such a pain in my ass that I ended up reinstalling my OS twice just to find out that linux policy functionality is a POS. Never had that problem with XP eh? Anyways, the answer was found here as of 2019-06-23.

After a fair amount of hair-pulling, I finally decided to use wildcards, in the interest of preserving my sanity, as suggested by https://github.com/coldfix/udiskie/wiki/Ubuntu-Debian-installation-guide.

I created the file /etc/polkit-1/localauthority/50-local.d/10-udiskie.pkla with the contents:

[udisks]
Identity=unix-group:plugdev
Action=org.freedesktop.udisks.*
ResultAny=yes
[udisks2]
Identity=unix-group:plugdev
Action=org.freedesktop.udisks2.*
ResultAny=yes