Yes, you can hot swap the batteries on the MōVI XL, but extreme care must be taken to avoid damage to the batteries, and to the operator.
NOTE: When you have one charged and one depleted battery connected to the MōVI XL, current is flowing from the charged battery into the depleted battery. This is the equivalent of fast-charging the depleted battery, so care must be taken to minimize the time spent in this condition to avoid damaging the depleted battery. Completing the hot swap within 60 seconds should help to reduce the small amount of additional wear and tear on the batteries due to hot-swapping.
WARNING: Motors should be disarmed before battery hot swapping.