We could also consider block/'foo to mean a WORD!-search. Or we could try for block/['word] or block/[word:] or block/[<first> #second] as a way of searching for a general value or sequence of values.
It's just my feeling that the randomness of "I don't know what type it is" probably doesn't have a lot of good usages.
(Note: Since pathing itself has no refinements, any searching it does is fixed on a certain choice of "equality".)
The odd-numbering doesn't strike me as particularly useful in the dialect-driven world of Rebol. I kind of imagine formats where I might throw in comments or strings or have a dialect that augments some assignments:
stuff: [
{Maybe strings are commentary}
cool
x: 10
y: 20
/cool
]
It seems that being able to query SET-WORD!s is more generically useful. Maybe even to the point of never returning a SET-WORD!, but to keep skipping. So block: [foo: baz: 10] where block/foo and block/baz would both come back with 10.