I want to be able to tell all the other sprite to go to back layer, but I just want to drop the my [other sprites v] reporter into the dropdown input to tell all of those sprites to do something, instead of running a for each item in loop.
so it's basically like
you can broadcast something to a list of sprites, but not tell a list of sprites to do something? That doesn't make sense.
I feel map should do this but
It worked for the 1st sprite - it said hello for 2 secs but then the error msg appeared
even trying it with the same sprite twice failed on second iteration
Well I think you want to tell 3 sprites to goto the back layer one at a time in order
Is that correct?
I just want them all to go to back layer (no delay), but this feature request would help in a lot of other situations, and since we have hyperblocks, you can broadcast a message to a list of sprites, it would make sense to be able to tell a list of sprites to do the same thing.
My understanding that this is what map is for - to iterate over a list and perform operation(s) on each item in the list.
So that all the blocks can operate on lists and not just list category ones.
And like you mention, Jens is adding hyperblock action when appropriate but I don't think trying to hyperblock something over just a few items would be worth the effort but lets see what he says 
what if you had a lot of sprites that you wanted to tell all of them to do something, but instead of using the for each item in loop, it would be better to use hyperblocks, since they run at the same time.
Hyperblocks comes into its own when doing operations over many thousands of items in a list (e.g mapping over pixels in a costume or samples in a sound)
I'm assuming you can visually notice the sprites changing their z-index at the moment?
And warping the for loop doesn't help (or introduces other visual disturbance) ?
"report" should do the trick
MAP is for reporters, not commands. The expression in the first input must report a value, so MAP can include it in the result list.
You could get away with abusing MAP by saying
In the initial implementation of hyperblocks we limited them to reporters. We're talking about extending the idea to some command blocks, and then, yes, TELL would be a strong candidate. But probably not soon.
