Unsquare post and joinery questions

[Cicatrix]

Tried to read as much as I could on here- lots of good information!

I decided to give it a go and attempt a small 10'x12' sugar shack build from EWP and spruce from my property. My posts are 7x7, they are within 1/8-3/16", 1" nominal shoulders for the 7x8 tie beam to sit on, using wedged dovetail joints.

I did a test joint using a piece of square true 7x7 for the post and tie beam and it came out okay but I have some questions.


1) The one post is unsquare, it has two parallel faces though. I marked the reference face with a blue X, and oriented it level in the vertical plane then put a framing square on and leveled the horizontal part of it using a small wood shim. Using a second square with the small legs overlapped and clamped, I then pulled my measurements off of that on this opposite face that is parallel to the reference face. Before I cut anything, is this the best way to deal will this situation and will it be accurate?





2) When the post is under 7x7,  drawing the slope of the housing up from the back of the shoulder, it runs off the side of the post  before reaching the control point/ top of tie beam causing a shorter vertical housing <7 1/2" (Tie beam is reduced to true 7 1/2"-resulting in a small gap, how do you avoid this?

Appreciate any advice you have,
Steve

[Cicatrix]

I think as far as #2 - the slope of the tenon cheek is the same regardless of the post being 7 or 6 7/8". Solution being to increase the depth of the shoulder to get rid of the gap at the top of the tie beam between it and the post.