Oibaf provides excellent packages, but they are cutting edge, short term only.
You can try the Ernst mesa cutting edge:
sudo add-apt-repository ppa:ernstp/mesarc
Then remove the Oibaf repo.
Run
sudo apt update && sudo apt full-upgrade
For the kernel, there are several ways of installing a later kernel (I recommend later than 6.14), and all of them are easy.
You can use the Mainline installer.
I prefer the TuxInvader kernel.
Secure Boot must be off since Microsoft has not signed the later kernels in most sources.