I think we need consistent pattern, so changing the pattern based on inspector position, number of options, … feels bad from my POV. I agree that the solution is not perfect in all case, the perfect for all case is a bit like unicorn, powerful but hard to get them
The solution in the middle column, is just a small change to improve the visual loundness and constrat issue of our current UI pattern for dropdown.
The right column, is an alternative solution (currently my prefered one). It has some small drawbacks, but also solve a lots of issue (not enough visible options, big dropdown down in the inspector, …) and open new possibilities like more rich options with more content, visual, …
For small dropdown with between two or five options, I will prefere to introduce a new rendering (radio/check box style) and make them visible all the time. A raw version can be something like this:
First draft, need more love