sizcoz
here is a different approach I worked on yesterday for a while - until I saw how awesome yours was :)
so, it is only a proof of concept - based loosely on examples ROJOhound made years ago to have objects follow a path. The code is very quick and dirty.
it is frame-rate dependant, doesn't use bullet behavior, objects can only travel one direction around the path, the path would have to be regenerated after any changes to any blocks... right now it generates the path at the start of layout.
but you can go as fast as you want! and once the path is generated, there is very little cpu usage - each object just needs to know how much farther it is until the next path node, if it over-shoots it, it backs up to the target node and then heads to the next one.
https://www.rieperts.com/games/forum/Minions.capx