I'd guess 1 would be faster than 2.
Parking at Pop and catching a bus to MK would be faster than 2 - you could check the screen to see how long before the bus arrives and if it's less than the wait for an Uber, wait for the bus.
Those are the fastest three options I can think of if you are picking up a rental car at MCO.
One one hand
1. google estimated time to drive MCO to Pop, plus
2. 5-10 minutes to call for and wait for Uber, plus
3. google estimated time to drive from Pop to COntemporary, plus
4. 7-10 minutes to walk from Contemporary to MK (not including security, which is same either way)
On the other side
1. google estimate time from MCO to TTC parking lot, plus
2. walk or shuttle from parking to TTC (time required highly dependent on time of day, ie how close do you park) plus
3. your estimate of time to monorail from TTC to MK including wait, which I would rate at 15-25 minutes absent mechanical problems, etc but I suppose that's debatable, (and also not including security)