I've had MW 6SN7s and agree MW Sony with Lundahl transformer coupling and 6922/e88cc are more transparent and neutral. I wasn't planning buying another MW except Sony is a completely different design so was curious.
Your description does make me wonder how the Atlantic would pair with a stock sony.
Sony digital out is stock and doesn't need MW tube analog mod so shouldn't matter. As matter of fact, PS 9.0 is off when I use digital out.