Why the desire for plastic? Lighter weight? Better sealng lid? More options? Newer looking?
Curious minds want to know!
I actually like them too, but I am avoiding them and staying with some type of metal just to avoid a catastrophe where there might otherwise be none.
In a situation where you might have a short flash fire under the hood from the engine, it might be enough to melt a plastic master cylinder and leave you stranded.
Where an iron or aluminum one might last a little bit longer while you put the fire out.
Kind of out there in left field, but I’ve seen enough fires under the hood over the years to always have it in the back of my mind.