TLDR: with higher speed designs, there is not much info in the hobbyist space, because the designs get more complicated in terms of pcb layout, signal integrity

TLDR: with higher speed designs, there is not much info in the hobbyist space, because the designs get more complicated in terms of pcb layout, signal integrity and so on, and a lot of the tools used for more advanced PCB design work are unfortunately closed source. That said it is possible to do successful high speed designs with some rules of thumb that 90% would work on the first board dev. And open source tools like KiCad are getting there in terms of feature parity with the closed source tools. Happy to talk, my contact info is in my profile.