Think you can do at machine and avoid the counter with
Alamo. I am sure an expert Alamo renter at MCO can tell you BUT I used Alamo in PHX a few years back with Costco discount. At time I wasn't good renter and didn't know how to use machine so I went to counter. Believe it or not lady did ask for my Costco card...thankfully I had kept that in billfold. Know there is way to bypass counter with most rental car companies so you shouldn't have to worry.