PE pipes used for NG seem "good enough" https://www.pe100plus.com/PPCA/HYDROGEN-TRANSPORT-IN-POLYMER-PIPES-FOR-NATURAL-GAS-DISTRIBUTION-TEN-YEARS-OF-EXPERIENCE-p1737.html
PTFE is known to be better. Fiber reinforcement is mostly an outside layer to increase pressure resistance. Putting PE or PTFE inside existing steel pipes would also work.
H2 only FC ebikes are not well developed or popular yet. Drones with FCs are actively developed as density/weight is a huge factor for range. Very small fuel cells, 500w or 1000w have applications in powering a home (with solar supplement) because they can run 24/7 and charge batteries. Hooking up torches or burners to these cannisters can also provide clean indoor cooking or heating a box of sand/water in a room.
For an ebike, it is touring/camping applications that this really enables. Charging a battery when you need extended range, and it becomes worth the extra weight. Even a 100w fuel cell slow charging a spare battery while riding is big range extension, and provides overnight full charge. Combustion cooking and heating is fine for high supplementary energy.
A H2 economy would have these cartridges in similar locations to swappable propane tanks.
Toyota research and products are ahead of their time relative to cheap green H2. This is an advance over using 300bar "paintball tanks" by going to 525bar, and it looks a bit like an apple product design. Needs far more electrolysis production capacity and deployments. The global project pipeline is long though, so we should get there. Current focus is on large scale electrolyzers with specific offtakers which is slow, but a step towards broader distribution.