I've been mainly buying tinned pipe tobacco and haven't been transferring to jars yet, about how long should I expect a tin to keep this way? I've probably made the mistake of opening too many tins of different tobacco at once and not smoking them up fast enough.
Also, how many leading blends have Latakia in them, all the ones that sound good to me seem to be a lat blend.
My experience with the commercial tins is that after the initial seal is open, they are really only good for tobacco storage for a couple months, tops. Even at that point with some tins you'll find the tobacco significantly drier than it was when first opened. What I started doing is I'll get tins I want to sample, I'll open them, leave a small amount to sample in them, and I'll mason jar the rest of the tin for longer term storage. If I finish off my "sample tin" of the blend and really want more of it, I'll just grab the small jar and put it onto the current rotation shelf. I probably have 18-20 blends on that shelf at any given time.
As for how many leading blends have lat in them, anyone's guess is as good as mine would be. Not even sure how one could even begin to guess on that one.