Complex sentence: The bootee should not be so thick, however, that it cannot be worn with the leg of a wetsuit pulled over it and restricts the ability of the surfer to grip the board with the toes in the desired manner.
Split into simpler sentences: The bootee should be thin enough that it can be worn with the leg of a wetsuit pulled over it. Another concern is that the bootee should not restrict the ability of the surfer to grip the board with the toes in the desired manner.