the # for each item in ≡ needs to be changed to
. it needs to manually throw an error because, the is ≡ linked? block doesn't report if the input isn't a list, and that makes the if <> block wait forever, and will break the snap! session. also, the warp block is removed because Refresh problem with [#] for each [item] of [list].
the type of block is found in dev mode, and still works in user mode.