Coming back onto ship last fall at San Juan I had 2 cans in my purse and the gentleman manning the scanner just looked at me, smiled and waved me thru. It was a good day!
I'm right there with you. I compare it to a coffee drinker being told there will be no coffee available onboard the ship but you can have tea. It's just not the same!
I don't think I would for a 7 or 14 day trip but on our longer vacations I do start to miss my go to treats from home and pick something up along the way. Unfortunately, Mountain Dew can be a challenge to find outside the US😔
I suggest you read some of the blogs from previous World Cruises that aren't on Cruise Critic. Many times they will mention specific travel agents that you may want to look into.
There is a limit on how much spending credit you can receive. You receive 1 day credit for every $300 spent. I think the spending credit is capped at the number of days of the cruise. So on a 14 day cruise you can only receive (an additional) 14 days of credit from purchases.