I know but being new would welcome those with more knowledge - but thank you for your sarcastic response....
is there a gap in time between check-out and re-check in?
Not sure the question was as sarcastic as it may have sounded. More about seeking additional information.
A split reservation doesn't always require a mid-week move if both units in the split are the same unit size. It all depends on the resort, season and how full the property location is at the time of the split. It costs the resort extra to clean twice so they will keep people in the same unit where it's possible, even if it is booked as a "split" reservation. Must be "like" units to create the non-move possibility.
That being said, to answer the original question, again, depends somewhat on how accommodating the resort management is relation to a split reservation move. If Check-out is at 10:00am and you are required to actually move, then for sure you have to be out of the unit by the stated 10:00am deadline, thus creating an inconvenient gap in time of where to put your stuff in the interrum before the 4pm check-in. However, many of the resorts will assist with easing this gap by assisting with moving luggage, food items in the refrigerator and/or storing guests personal items during the gap while they continue other activity for the day.
Would for sure call the resort in advance of check-in and discuss the split. It's a courtesy for them to help manage the inventory and it helps the travelers to know what to expect and how to plan. Also discuss at check-in as they only look at one reservation at a time. Communication helps the process for everyone.