The weight restrictions with the centre gear retracted are:
MTOW 199.6T
MLW 164.9T
MZFW 158.8T
The MTOW is approximately the same as a -15 (204T). So with it retracted the aircraft performance is similar to a -15 (-50C2R engines) as opposed to a -10 (-6 engines).
But with MTOW reduced by 67T this is a huge penalty for long haul operations
But
for short haul
No other restrictions apply except in the event of a dual hydraulic failure, involving the landing gear system, consideration would be given to maintain the centre gear retracted.
Merry Xmas