Are you able to point to documentation or code that supports the claim that “ticks are executed asynchronously (if multithreading is on)”?
Writing code/blueprints to support that scale of multithreading is relatively advanced. Every access (read or write) to anything shared must be protected by a mutex to be threadsafe.
I’m pretty sure that the ticks in each tick group are run in serial on the main thread (though nothing prevents a tick from firing off some work to be done in parallel).