Worked example.
Two parallel bookings.
Friday > Monday
Satruday > Monday
I try to add in bike M3 to the second booking. BRM rightly detects the clash and doesn't allow:
Then I go back to the first booking - the blue one - and check it in early. On Saturday:
Reservation goes Green.
Bike M3 is made available upon check in.
Then I go back to the second booking and add in M3 which now works: