As you know For Each works as a system loop, and can be cpu intensive if you have many instances.
I would like to propose an addition that would alleviate some of that.
Basically instead of picking each instance every tick, you pick a single, or loop over a smaller number of instances like an array each additional tick. For example if you had a thousand instances you do a mini "for each" over say a hundred in one tick, the loop over the next hundred in the next tick, then repeat at the end.
I know that you can already do this with "pick nth", or via instance variable, but as a system command it would alleviate some of the confusion for newer users who may not understand how For Each is supposed to work.
I think the only real concern would be how to iterate, ascending, descending, and other evaluations such as y,z, etc.