Expand/Collapse icons of Folders for Fields needs to be consistent

Depending on where you are in the program, the icons that indicate the Expand/Collapse availability is different.
*From the user perspective in a Matrix or Hierarchy, it is Plus and Minus signs (+ / -).
*If you are looking at the Relationship pane and have placed a field into a "Display folder", then the icons (on the Relationship pane) will be either a right-pointing triangle or a triangle that points down and right (with both triangles being filled in a solid dark color).
*If you look at the Fields list in the Reports pane, then those Display folders will show with either an upward or downward pointing carat (^ / v).
*If you look at list of submitted items in Visual Studio Feedback forum, the icon set is a right pointing carat and a downward pointing carat (> / v ).
*If you use Visual Studio to develop Tabular models, then you have a set similar to the Relationships pane in Power BI Desktop, with the difference that the right-pointing arrow is hollow.
*If you are on Power BI Service, they have introduced a LEFTWARD pointing arrow for Workspaces. And for content INSIDE a Workspace, there are NO icons to indicate expand/collapse state of the groups (Dashboards, Reports, etc.)

Seems inconsistent that the EXPANDED icon on the Relationships Pane points DOWNWARD (and to the right), but on the Reports pane, the EXPANDED icon point UPWARD!

Why is this important? It's about PATTERN REGOGNITION. If I see an arrow icon that points in a certain direction, I should be able to do pattern recognition IMMEDIATELY and not have to stop and consider the CONTEXT in which that icon is displayed.

Oh how I wish Microsoft would be CONSISTENT on things like this, and terminology.

Personally, I prefer the (+ / -) set.
Honestly, I think it's a lack of oversight and quality control.