Interesting you bring this thread up again.
I was wondering about something on these lines.
Firstly though, it is not easy. If you check
https://gbatemp.net/threads/wii-u-menu-sort.455132/
you'll see the layout for the icons and a defined 300 limit is embedded in the nature of the system code.
No simple change of a couple bytes is going to help us here.
However, I'm wondering if it maybe possible to access more than 300 titles via a 'trick':
My theory is your WiiU USB disk can hold any number of titles installed to it but it will only allow you to access 300 of them.
From what I understand from
@Yardape8000 post, the titles displayed are those defined in
/storage_mlc/usr/save/00050010/10040200/user/80000001
in a file called BaristaAccountSaveFile.dat
So, if you configured a new BaristaAccountSaveFile.dat containing the non-displayed title ids already stored on your WIIU HDD, and switched it into place of the old one,
would this not then allow access to these titles.
If so, then all we'd need would be a simple homebrew to switch different active copies of BaristaAccountSaveFile.dat