Inconsistent border thickness between icons and cast bars with "unit frame thin border" disabled in ElvUI

[nawuko]

Describe the bug
Using the "unit frame thin border" disabled setting to create borders around the UI results in inconsistent border thickness. Icons seem to have thicker borders compared to cast bars. This inconsistency becomes more apparent when borders are enabled, as it seems ElvUI may apply borders differently to different elements (sometimes to the outside, sometimes to the inside).

To Reproduce
Steps to reproduce the behavior:

1. Disable "unit frame thin border" in ElvUI settings to enable borders around UI elements.
2. Observe that the borders around icons are thicker when compared to the borders around cast bars.

Expected behavior
Borders should have a consistent thickness around all UI elements, including icons and cast bars, even when "unit frame thin border" is disabled.

Screenshots

Additional context
The issue seems to lie within ElvUI's handling of borders across different UI elements. A potential solution could involve overriding ElvUI's border settings and applying a uniform border definition across the UI to maintain consistency.

[nawuko]

This comes from ElvUI's side, like stated in the issue, the calculations are off for double borders in quite a few cases. Just reducing the Icon Size by 2-3 pixels solve that, if the user decides to enable bold borders they have to deal with decreasing the size by themself (this is also the case for buffs etc) - Changing that behavior in ElvUI could have side effects therefore this will be not fixed from our side.