drivers – Hardware Works Well on Older Kernel – General Question

I am running 20.04 with the 5.4.0.26 kernel on a 2017 iMac. I have stuck with this kernel because the two Thunderbolt displays that I have attached are instantly recognized and function perfectly. This only happens with this kernel – I have tested many others extensively.

I am starting to learn more about Linux and I anxious to upgrade my kernel to a more current one, but the Thunderbolt monitors flicker badly and never work as well as on kernel 5.4.0.26.

Generally speaking, given that I know that these displays are at least capable of working perfectly on a certain kernel, should it be possible to learn what works well on that kernel and translate it to a newer one?

How would I go about doing something like this? Ideally, I would like to learn what makes my hardware work well under this older kernel and translate those fixes to a more current kernel.

Any help would be most appreciated.

Thank you