0n page 27 "...most basic strategies are created to apply specifically to either single or multiple decks, in practice, we have found it best to memorize one generic basic strategy table. This is because the gain in memorizing additional variations is very minimal, amounting to a total additional gain of roughly 0.03% overall." My intuitive gut feeling ( i'm no mathematician) is that you would give up less by using the same BS in 6-deck as you do in 2-deck than if you used the same BS in 1-deck as used in multiple deck. I use KO, but I use separate BS for 1-deck vs. multiple deck. In my experience 1-deck is extremely sensitive to playing strategies (including using correct 1-deck BS), but the difference between 2-deck & 6-deck is not as pronounced. So, I would say go ahead & play 6-deck with your 2-deck BS & you will not be giving up much. Good cards to you. KO EWE.
Jack - You may want to fine tune your S17 vs. H17 BS if you are going to shift back & forth. I never play the shoe. I play 2-deck @ low minimum tables & therefore 99% of my play is H17 & therefore I don't bother with a separate strategy for each. I do adjust my splitting re: DAS vs. no DAS. It seems I play about 50% each, but these are simple adjustments for me. 4,4 vs. 5&6, 6,6 vs. 2, 2,2 vs. 2&3 & 3,3 vs. 2&3. These changes do fall into the 'learn one way' category, but as you have perceived, they are so easy to learn I incorporate them into my game with ease. I do believe in the KISS approach & only go to extra effort & complexity on those things with the highest expected value. For example, I use KO & the authors readily admit that most of the power is in the betting efficiency & not the playing efficiency, so I usually employ the top 16 playing indices & don't worry about memorizing 100+ playing strategy indices. I don't recommend this approach if you play 1-deck, but it certainly applies if you play 6-deck. Heck, if you really want to relax memorize one BS, your bet ramping numbers & only 2 variations from BS(taking insur. & when to stay on 16 vs. ten). Goods cards to you. KO EWE