@darwindesign You’re right, thank you!
I just figured it out myself, shortly after posting and updating a moment later that I nocited it actually does a right-click :). That pointed me in the right direction, and from there I simply refered to Kodi’s official Wiki, specifically the remapping section regarding mice.
What you said is exactly what It did, the only difference being that I chose the “Back” action instead of “PreviousMenu”.
My ~/.kodi/userdata/keymaps/mouse.xml:
<?xml version="1.0" encoding="UTF-8"?>
<keymap>
<global>
<mouse>
<rightclick>Back</rightclick>
</mouse>
</global>
</keymap>
My ~/.kodi/userdata/keymaps/keyboard.xml:
<?xml version="1.0" encoding="UTF-8"?>
<keymap>
<global>
<keyboard>
<key id="61576">ActivateWindow(Home)</key>
</keyboard>
</global>
</keymap>
So now I have exactly what I wanted. The back button going back, and the home button going straight to the Home screen :).
Gosh, if only I noticed that it was actually doing a right-click earlier… that would’ve saved me sooooooo much time!