Hi @designfilter & @Garret_H
As I mentioned above, we are looking at 2 projects, the first, is "Flip Arrow", this one is underway and will be available in an upcoming build. The second project will give you more flexibility around arrow heads. Internally, the project is called "Object properties MVS2" - partly shown on the roadmap as "Leader Styles"

With "Object properties MVS2"/"Leader Styles", you'll be able to specify the type of arrow that you would like to see on your dimensions. Our UX team has recently finished the designs for this, and the development team will be starting work on it very soon.
An update since my last reply to @jonathan.watson.usa, We are working on adding even more flexibility to "Custom" text height groups, this is also part of our "Object properties MVS2" project. Since my last reply, model sketches can now be tweaked to look the way you'd like. Their line types and color can now be changed in document settings.
I'd like to invite anyone on this thread that wants to give direct feedback to the team, or wishes to dive a bit deeper into what we are working on, to please book a 30-minute session with me, and we can chat on Zoom. Here is the link to my calendar, I can also share some of the future projects that we have in the works (see the public roadmap here). I'd love to hear from you directly! Or if a good old-fashioned email is more your style, feel free to ping me Clint. Brown {a} Autodesk.com