Quoting myself…
It seems my “IIRC” was wrong. Can’t make it work with KM7. Must have mixed it up with some other thing.
And, before you ask: Yes, I still have one Mac with KM7 running. Shame one me. But the sole purpose of that KM7 Mac is to verify whether something I perceive as new with KM8 really is new. Or vice versa 
Here is an example of mine how I used the new KM8 features in a macro:
Macros for Retina Screenshots on the Forum
- The macros are exclusively using local and instance variables
- Since some of the macros are executing another macro, it may serve as a demo where to use instance variables and where to use local variables.
- One of the macros also uses a Calculation token in a regex replacement (apparently without me knowing that this didn't work before ;))
- The new operators of the If…Then action (for example "<=") are used.