Mark –
With very few exceptions my frames tend to be English Tieing, usually scribe but I have SR’d a few also.
I know this speaks only indirectly to your main question, and won’t help being at the stage your at, but I long ago abandoned the dovetail for the cog & clasp, it just doesn’t share the same shrinkage issues. Interestingly while at the Clumps event I asked a number of our Brit friends about this, and it seems to be a common practice on their side of the Atlantic also.
As far as cutting goes, be sure to connect your datums and draw your teazel’s end before you make the end cut for the plate tenon. Usually the Jowl is too large for the clamp of the mortisers, so I deal with this by screwing a two by block, ( aligned parallel to the datum ) which has a three inch wide slot cut in it, to the post and clamp the mortiser to that ( tending to grab the HCM if we’re working pine ) and use this to cut the crotch between the front of the plate tenon and the jowl.
I tend to hand pick saw logs ( my main supplier indulges me and lets me cruise his log yard even though he wants nothing to do with milling them )with very heavy butt flair to mill the jowl posts, so the grain flows back into the posts as was traditional. and even often opt for the English type true jowl ( when a project merits it ) instead of the taper more typically found here in New England.
Hope some of this helps.
Best with it,
