I don't do sft....only time that I do is when I'm feeling bored with everything or lazy....
while sft may be a good idea, it doesn't really help much because they will taste different with different flavors
as I've said before, what sounded good in my head didn't turn out so great, some flavors just don't go well with others...
so I mean ok you did a sft and it was nice, you used it in your mix and now it's not so nice....the sft was more of a waste of time/wick....the only thing that an sft is going to do is tell you if the flavoring has an alcohol or perfume taste and will need to steep with the cap off....which you would find out after mixing as well
typically a flavor is going to mostly taste like what it's supposed to (though everyone tastes things differently), I try to read any user reviews on them before I purchase just to make sure that it doesn't have some funky taste or something
me I just dive right in and make a mix and then go from there
also since I use rdas I just vape my wick dry before trying a new flavor, instead of changing the wick...if need be then yes i'll rewick but usually just dry vaping and then doing that a few times with the new flavor will be just fine...