I imagine steaming is the same concept for fermentation
Steaming actually destroys both major, intrinsic oxidizing enzymes that bring about fermentation as well as subsequent aging. Steaming cooks the tobacco into Cavendish.
Freshly cooked Cavendish will change noticeably with time, as some of the harsher volatiles dissipate. Think weeks to months of "resting", after cooking the Cavendish. Just sample along the way. Burley and Virginia (I assume it was air-cured, rather than flue-cured.) can definitely make an enjoyable blend as a Cavendish.
I divide tongue bite into "front of the tongue bite" (low pH—too acidic) vs. "back of the tongue bite" (high pH—too alkaline). When using
flue-cured Virginia, which is considerably more acidic than burley, a roughly 50:50 blend of VA and burley works to balance the pH. Using
air-cured Virginia, I would suggest starting with 80% Virginia to 20% Burley, then adjusting the ratio to try and eliminate whichever tongue bite you detect. [If front of the tongue bite, then increase the burley. If back of the tongue bite, then increase the Virginia.]
For next year: An inexpensive method of curing Virginia without a flue-cure chamber is to string the mature, freshly primed leaf, and hang it in the sun to sun-cure (like is done with most Oriental tobacco varieties) for 2 to 3 weeks, shielding it from rain . This results in sweetness and acidity that is between what you get with air-curing vs. flue-curing.
Bob