If the vehicle is idle WRT load for the required amount of time I would concur. Not clear from OP that it was not clear about the Forscan load. At least that is how I read it.But you're only using ForScan to check the SOC- after leaving the vehicle sitting with everything off for the required period. You don't leave ForScan running while the vehicle is sitting there.
I just double checked the parameters for the calibration to take placed- it's <100mA for >3hrs. "The battery monitoring system requires calibration at regular intervals of no greater than 7 days. If a recalibration hasn't been done the exact SOC of the battery cannot be confirmed."
I also came across the bit mentioned elsewhere about "sulfation occurring if the battery is at more than 80% SOC" and I get the feeling they've made a mistake in the WSM. I think it's meant to say sulfation can occur when the battery is less than 80% SOC for a long period of time. The reason I think it's a mistake is they then go on to say a "refresh charge" is done to fix the risk of sulfation. The refresh charge involves charging the battery at a higher voltage of 15.2V. Charging the battery to a higher Voltage is going to raise the SOC higher than 80%- it doesn't make any sense to charge the battery at a higher voltage if >80% SOC causes sulfation. (Plus it goes against every other website regarding charging lead acid batteries and how to reduce sulfation taking place. The normal recommendation is to fully charge the battery as soon as possible after discharging it. You shouldn't store them partially discharged.)