Custom Guitar Hero GH5 Guitar. Has mechanical frets and strum bar, removeable USB C, and multi-platform support.

This guitar works on pretty much all consoles, it is plug and play on Xbox 360 and ps3. For Xbox one and Xbox series consoles there is a USB port in the wii cover of the guitar, plug in an Xbox controller and it will make the guitar work on the console.

For Rock Band 4 on ps5, all you need to do is load into the game and plug in the guitar and it will show up. For Xbox the usb plug on the guitar is used for as described above.

For Fortnite festival, plugging in the guitar well holding down start on the guitar will make it show up as a keyboard and work natively.

Mod list as follows.

Kailh white LP mechanical fret switches

3D printed strum bar, D-pad, and Wii front and back cover. 

Box navy mechanical strum switches. 

A pi pico controls everything, running Santroller by Sanjay on GitHub. This allows all the features said and allows you customise things like the tilt angle of the guitar.