Hmm.. The Grifta looks like half a gamepad. Benefits would be that you don't just have D-pad and thumbstick but also buttons.
Traditional devices are analogue flight stick, and digital arcade stick.
Flight sticks are often right-handed, but with a few buttons, while arcade sticks have none for the left hand.
There are "gaming keypads", like half a keyboard (or less) for the WASD cluster: where many have joysticks for the thumb, but some have just digital D-pads.
The Hori Super Robot Wars for the PS1/PS2 is a gamepad for the desk, with D-pad on the thumb but the two analogue sticks straight up. That one could perhaps be used with an adaptor to USB. (There is also a Playstation game called Super Robot Wars... so always search for Hori)
Edit: Found similar device called DragonPlus RPG DuoCon 2.
Microsoft SideWinder Strategic Commander is a weird device. It is like half-way between a large captive mouse and gaming-keypad. You'd slide the whole thing around to actuate the joystick. The buttons are microswitches like on a mouse. I think it requires drivers that are not available for modern Windows. Because I haven't got it to work I can't tell whether it is digital or analogue.
