Standard containers are 20 or 40 foot. Shipping and storage capacity are measured based on the 20 TEU. Standard height is 8.5 feet. There are tall containers (9.5 feet) and long ones at 48 feet, Width is 8 feet. There probably are some 24s out there as half 48, but it would be an unusual box for international shipping.
There are at least twelve 24s. Likely more are being built or at least contemplated. Most of the Chinamax ships are too big for Tampa which can only handle 10s, and the canal can only handle 14s. The 14s would have to go to NY-NJ, which is already backed up.
Anything coming from Asia over l4 to 16 would have to go the long way around - assuming the cargo would not suffer from the extra time.
So again Florida would not be much of a help, if any, on the shipping backlog.