Their load data specifies a max OAL of 1.2".
Sir, if you look again, you won't find the word MAX in front of the load data oal.
The load data in the manual is actually the MINIMUM safe oal for that load.
The OAL load data gives will result in the pressures and speed the manufacturer saw with that load.
If you load LONGER than the load data oal, the pressures will be LESS. Less pressure is safe to load.
So if it shows an oal of 1.20 and you load 1.25, the load pressure and speed will be a little less than the shorter oal would give. No problem.