How about just making the fancy terminal a straight cut -- at first.
Work out the whole glyph set that way (and test it in small text), and then apply the extra nuancing (if really necessary).

That may seem like a lot of work and going backwards, at this point in time, but it would resolve design issues by separating letter shape and letter detail, shape being the more fundamental and having priority, and be more amenable to adding extra weights.

Design the process.

(Many people work this way when producing rounded fonts, by producing a "normal" sans, and then applying the rounding.)

.

Seems like quite a logical idea, but I think I've tried this before some time ago, without succes. I'll give it another try, but I think the 'fancy terminal' just has too much influence on the curves.

The G looks too narrow as well.

And so does the O.

I have not measured the widths of your strokes,
but it appears to me that the width of the widest
part of your curved strokes may be mechanically the
same as the width of the upright strokes?.

For optical reasons the widest widths of curves should
be a fraction wider than the vertical width.
But this will be a visual decision and not a mechanical pecentage.

Ieuan Rees

Yes I came across this problem a few months ago, but to my eye it looks balanced now. Myriad only has a very small mathematical difference between stems and curves compared to expletus.