Support is a very individual thing, we all need different things. I like the not well known Safestyle composites but generally recommend borrowing as many as you can to see what you get on with.
I borrowed some Shires composite stirrups with metal treads. They were OK but I’m used to metal and rubber bendy stirrups. I’ve used those for years to stop ankle and knee stiffness and pain.
I couldn’t find any lightweight stirrups with bendy sides and flat treads except the Royal Rider Perfect Flex. They come with metal treads fitted and spare rubber treads. I was lucky enough to find some second hand as I was shocked at the full price. I’m finding them perfectly fine but still find it strange when running them up as they are so light. I use the rubber treads.
I think it is an individual choice and trial and error is the way to go.