Also, K1V WILL go to 18% if it has half a chance. Don't just assume it will stop at 0.998, since it can go lower than that. There are plenty of people who have had meads ferment far below 0.998 due to the yeast still being able to survive, and there being sugars left for it to go through.
I'd also leave out the tannin and acid blend out of the batch. You don't need it. Nutrients, degassing, and aerating will help it along. Otherwise, just give it time to do what it will. IMO, you're best off planning on giving a batch of mead a bare minimum of 10-12 months before going to bottle. Rack as needed (don't do the first until it's 100% FINISHED fermenting) but never more than once every 2-3 months (post primary).
You can add some proper tannins to a batch via oak aging. IMO/IME, that will do a lot of good for a batch (depending on what it is). My traditional (18%) that spent some time with oak is better because of it. Just be sure to give it enough time in all stages/steps. Do NOT try to rush this through.