How do hemp, linen, etc strings compare to Dacron when it comes to temporary/permanent elongation (stretch/creep)?

Good linen string is stronger and has less stretch than Dacron.  I have not used Hemp.

I have wondered the same thing.  If Linen is stronger and has less stretch then why did people swap to Dacron?

Because Linnen has a habit,of just lettin go and breaking,without much sign of wear n tear.Folks used to just change the strings out after so much use,just to avoid it happening.