That riding or whatever is currently implemented via an ATTACH procedure is an implementation detail, and should not be part of the interaction interface. We may someday decide that ATTACH isn't the best way to go when creating mounts, and code the whole mounting in script, and what do you suggest we do then? Rebuild a vast library of third-party objects that depended on your promise that any mounted Clonk will have its procedure set to ATTACH?

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Another related thing: A lot of the inertia in changing engine internals stems from the mostly non-existing encapsulation of core engine parts, which mean that a simple change cascades to a huge amount of indirectly related changes (because they depend on the exact internal representation of some values), which themselves cascade and so on.

> I'd say what you mean to check is not whether the action is named "Tumble or "Jump" (and thus give the action tumble a special meaning beyond what is defined in the actmap) but check whether the clonk's action has as a property ObjectDisabled=1 (and has the procedure FLIGHT, depends on the application of course)

No, he doesn't want to check for procedures and ObjectDisabled properties. He wants to check whether the Clonk jumps, regardless of how that may be implemented internally.