If I order a ship to board another ship, but then that other ship later explodes, there is no way to cancel the boarding action, and the marines never return to the inside of my ship. This leaves them exposed and stops them from acting as boarder defence.
I agree. Maybe add parachute marines?
they should add an option to just board the nearest ship, this means that you could board multiple ships if you are careful and that stuff like what you mentioned doesn't matter.