I suspect this is not possible, either that or I have really missed something.
I have lots of instances of the same sprite, I need to know when another instance of the same sprite is, say, 16 pixels above another (IE Y-16).
This is easy enough using the 'Is Overlapping At Offset' event, set Y to -16 and I get all the sprites with another sprite 16 pixels above them.
But is there any way of picking the sprite that is at the Y-16 offset? Using Pick Instance does not work because the picked sprites are only those with a Sprite at Y-16, not the ones at Y-16.
I realise I can have another event to look for the Y+16 sprites, but it seems really wasteful to have to do two overlap detection's when both sprites would have been found in the first event.