do plastics really hammer your strings that much? I've just popped zm65 after a month. 80/20 plastic/feather play time. was a miss-hit but the bed was peppered with fraying areas. same strings on old racket 1lb higher still going strong but mostly used on feathers. 20/80 playtime compared to above but had twice as many hours on court. luckily i now have a racket dedicated to plastics with .73 string in.
Ashaway power gut 65 is phenomenal for plastics. At .70 I hope that sorts my durability issues and I can save my thinner strings for feathers only on another racket.
I believe if the plastic shuttle has cork head like the the feather shuttles and has the adequate speed then the string will last the same time.
I think plastic birds are easier on the strings than feather. Due to the cost issue, my club almost uses plastic shuttles exclusively, and the string breakage for my rackets is a lot less than before. (27lb either with BG-80 or BG-66). It is possible that plastic shuttles fly at a somewhat liner or flat trajectory, the chance of miss hitting the shuttle is less (not to say that it is easier to play with them).