Bloopair VS Sonic-Mania-Decompilation-Wii-U

Not worth it. If you have a modded Wii U, bloopair is worth trying: https://github.com/GaryOderNichts/Bloopair

https://gbatemp.net/threads/hid-to-vpad.424127/ might let you use the GC adapter and real GC controller. Otherwise you could use one of the GC-shaped Switch pro controllers with https://github.com/GaryOderNichts/Bloopair

I had the exact same problem, still don’t know how to make it work, but maybe for you it will work if you download the latest version of the Bloopair on GitHub maybe it'll work to you =)

You need amodded Wii U, but Bloopair supports this. afaik there is no other way.

Personally, I think all of the “pro” necessary is available with https://wiiu.hacks.guide/#/ and a 500GB Seagate SSD. The SSD draws far less power than an external HDD, so a USB-Y cable is unnecessary. I have a Custom Firmware (CFW) Wii U and it, the OEM GameCube adapter, a few Wii U Pro Controllers, and the most recent release of Bloopair (https://github.com/GaryOderNichts/Bloopair) and one is in business for a very exiting and Pro Wii U gaming experience!

Solution-- use bloopair. Bloopair lets you use almost any controller wirelessly (including the switch pro controller), so HID to VPAD is a bit outdated now. If you have tiramisu, then install the tiramisu version here (This is the current version as of writing. Clicking on the link will automatically start downloading bloopair). But if you don't have tiramisu, you can manually install the legacy version here (This will probably always be the latest version because it's unsupported as of ver. 0.51. Clicking on the link will immediately install bloopair to your computer). I gave direct links for manual installation, but if you have the Homebrew AppStore then you can grab them there.

I have the same controller, and it worked with Bloopair, with an unofficial (yet) version. I followed this thread: https://github.com/GaryOderNichts/Bloopair/issues/56

I've been inspired by the BotW disassembly (see https://github.com/zeldaret/botw) as well as the success in backporting Sonic Mania to the Wii U (https://github.com/Clownacy/Sonic-Mania-Decompilation-Wii-U). So clearly this is something that's doable. The only minor complication is that this will require soldering a bit more RAM into the Wii U, I already did this myself when I made a portable Wii U a few years ago; should be no problem for anyone with even a modest background in EE. You would of course also need a soft-modded Wii U and external HDD to run the game; there are plenty of tutorials on how to do this.