Just another idea (I seem to have too many of them :D): Some kind of UnderlyingObjectAttribute (with a better name, of course) an editor can check the selection before compiling it when inspectIt/exploreIt is pressed?

Example 1: ('2 + 3' asText) -> User presses inspectIt -> Editor checks for UnderylingObjectAttribute -> none found, so the string is compilaed as usual.

Example 2: (Text string: '2 + 3' attributes: (UnderylingObjectAttribute for: 5)) -> User presses inspectIt -> Editor finds an UnderylingObjectAttribute -> instead of compiling the selection, the cached result is reused for the inspector.

We would not even need to display this Attribute visually if it works reliably.