It sounds like you are naturally arching your tongue, and that's perfectly compatible with K tongue modified. KTM goes with tongue arch like peanut butter with jelly. It's just that with KTM, the middle of the tongue (not exactly the middle, really; just not the very tip) strikes the teeth instead of the tip. I try not to think too much about it either, but when I'm going up in range it feels natural that my tongue tends to arch slightly higher and this means that it's striking (or being withdrawn from, however you like to think of it) a slightly different location. Again, KTM works for me, but if you can double tongue like a Gatling gun with another method (or no particular method) then I wouldn't stop you!