https://en.wikipedia.org/wiki/Hydrogen_embrittlement#Prevent... is a good start.

It seems to be mostly a solved issue if you use the right materials and design: https://en.m.wikipedia.org/wiki/Hydrogen_pipeline_transport#...

seems like it would be easily solvable with a plastic coating, right?

Hydrogen fuel tanks already have an inner liner to prevent this.

Hydrogen will go through plastics, in fact plastic containers need a metal coating to contain hydrogen effectively.