I get really confused about bark and descriptions.
Never really sure what the descriptive terms mean to different folks.
Here is what little I think I know.
For thick bark, I use lots of rub. For less bark, I use less rub.
I have even got a "bark" on brisket using just salt/pepper/sugar for a minimalist sort of rub. That was nice.
For a bit of firmness in the bark, I add more sugar.
If I want it even firmer, I add even more sugar.
If it is "crisp" or "hard" and tough to bite--I use less sugar.
I foil when the color is right and cook till tenderness is (hopefully) correct then cooler. I take it out of the foil and slice or pull as desired.
I describe my bark as "firm" but it not "hard" or "crispy". I do not feel like I will chip a tooth eating it.
I have never produced bark I considered "Mushy". I may be just lucky.
For ribs, I have tried a lot of sugar in the rub/glaze.
That gives a shiny smooth finish that looks really good.
But, when I slice, the caramelized coating has a tendency to chip or break off and does not give a clean professional looking cut. This is especially true if I have put them back on high heat to "set the glaze"--becomes like a "hard candy" if I am not careful.
I guess it is a matter of balance.
And, there is more to it than just the sugar amount. I just focused on one piece of the puzzle.
Just my thoughts from my limited experience.