You can upgrade the kernel if you want, however be advised that if you do so outside of what the Dev team releases then you are on your own for support.
On one hand it is good to stay "up-to-date" however on the other hand, doing so can indeed "break things" that are specific to the BT kernel, while this does hold true for most Linux distro's it is a bit more imperative for BT. As for doing an upgrade there is a blog post on off-sec with more details.
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