When HAL says "should you wish to make adjustments, you may do so at the end of the cruise by contacting the front desk." that is not entirely true.
We just completed a 14-day Alaska cruise on the Statendam. At the beginning of the cruise, we opted out of the $10/per person/day program, preferring to tip where warranted.
The following day a letter arrived rom the Captain stating "dining and cabin stewards are required to turn in any tips they receive directly from those guests who have removed or reduced the gratuities on their onboard bills."
Basically, HAL has taken away the customers rights to tip those giving superior service and not tip the ones who are indifferent.
After several letter and meetings with the Guest Relations Manager, we were then "permitted" to tip our cabin steward without his having to turn the money over.
We partially got around the problem by purchasing phone cards in port and giving them out as "gifts not gratuities". We also asked when birthdays were, bought a few birthday cards and once again gave gifts not gratuities.