You can't technically spawn something in a different layout because only one layout is really active at a time.
One way you could do it is have global variables. This would only be efficient if you are tracking a few.
spawn1 = 0
If something happens in this layout spawn1 = 1
On start of layout & spawn1 = 1 THEN spawn
There is also Global setting in the instance property:
By default, all instances are destroyed when the layout ends (e.g. when going to the next layout). If Global is Yes, none of the instances of this object type will be destroyed when switching layouts.
Maybe you could spawn in this layout, set to be inactive and hidden, then have it be global to carry over to next layout, then activate it. I haven't used this though so not sure if it works that way
There is also the persist behavior. Don't believe this would help if spawning an object in a different layout but would help if wanting an object to stay the same when coming back to a layout.
Hope some of that is helpful