Do "finish swivel" by the book (TGM) and the face should rest back on the plane just like it did on the backstroke/downstroke. Works well and may be "geometrically" correct.
If you do the finish swivel the "ben doyle" way it is technically "off plane" because it is now facing more towards the target than the plane but 2 things will happen:
1) you will hit the ball lower
2) you will hit the ball farther (smash factor)
I have proved this via launch monitors time and time again. It's just like "someone" said in an online video, "sometimes you want to maximize compression and sometimes you don't."
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I'm not a TGM or PGA certified Pro, but I did stay at a Holiday Inn Express last night