I was looking for help with radius visualisation as well and found this post.
Maybe you also still need this.

I was able to add a visualisation area by adding the radius_visualisation_specification property to my new assembling-machine prototype like this:

radius_visualisation_specification ...

Is there a way to add a unit to a spawner after it has been removed from a spawner with LuaEntity.release_from_spawner()

The only way I found, is to set the unit command to wandering and wait. but there is no trigger event to check when the unit has been reassigned to a spawner and it might take ...

in the control stage, recipes are unlocked for forces. You can disable the old recipes for the force of the research trigger event.

script.on_event(defines.events.on_research_finished, function(event)
if event.research.name == "deep-mine-MKX1" then
local force = event.research.force
force ...

+1

I just found this request as I had the same issue with the artillery turret attacking enemy "dummy target entities" of the simple-entity-with-force prototype. I could also use the combat-robot or land-mine prototype workaround to keep the artillery from firing at the dummy entities but just ...