[Aren Siekmeier]

We have used global variables rather extensively, and typically run the data sink in a much faster loop than the data source, for example the data sink being a 5 or 10 ms drive loop with the data source being teleop at 20-50 ms. We haven't experienced noticeable issues with race conditions because the ones that might arise are short lived enough with a comparably steady state input signal (changing much slower than the output updates). Similarly with sensors, we've had the timing such that any issues that arise are fleeting and insignificant. We have enjoyed the ability with a set up like this to easily move control of the functions between teleop, autonomous, and various automated routines by having them tag team on the updating of globals which command output state.

I can't say I know much about the other options you listed outside of their existence and basic operation.