I found that if R2 in a controller emits signal as both an axis and a button, it can interfere the left stick assignment and be wrongly assigned as left stick x axis. I changed the order so this can be avoided, unless a controller sending a touchpad click signal as an axis appears and gets popular.
A mapping for 'Unknown Gamepad' is also added. I found it appearing when my DualShock4 is plugged and not having its lightbar lighting. Since I believe DualShock4 is a standard DInput controller, I hope having this mapping made with it added to the repository is okay.