long term storage for tyres?

so i recently went on the search for tyres for my fzr 600 for the first time, knowing that the rear tyre will be hard found (150/60 R18) did hours of research on possible brands and i was limited to the bridgestone battleaxe in cotters, thats grand they came in the post today. but on the website i had the choice of a BT 090 or the BT 092, the 090 being a softer gripier tyre, the 092 being longer lasting.

when i went to order the 092 they said Bridgestone stopped making them and id have to get the 090.

so the thing im wondering is how long until they stop producing the 090 leaving me very very stuck for choice? so here is my question:

how long could you store a tyre without it getting dry rot/ going hard by taking all precautions? from looking online it seems to be constant temp, no sunlight, storing in bags (or vacuum sealed) and possibly putting on some tyre shine type of stuff

now i know i’m taking this a bit far but its more out of curiosity more than anything else :lbhbh:

also is there any way of being notified of a tyre being discontinued before it happens?

cheers lads