wouldn't it be really cool if they fill 056 up with visitors and then go out on a patrol cruise doing a full lap around the waters of hong kong? instead of the old 'come aboard a parked ship' thing every year.
The 056 is a warship, not a cruise liner. Civilians have no place on a warship when it is underway. No navy anywhere does what you suggest, for good reason.
The ship's crew all have duties and responsibilities when the ship is underway, and there would be few crew that could be spared to babysit a bunch of overexcited civilians. In addition a warship will not have the facilities onboard to accommodate large numbers of civilians. Spending half an hour or an hour on a tour is one thing, but those people will have basic needs that have to be met if they are stuck on a ship for hours on end while it does a lap around HK, even the most basic things like lavatories could become a problem if you have several times the number of people the ship was designed to support onboard and limited to non-restricted parts of the ship.
Even if you stuff the 056 to the gills, you will only be able to take a tiny fraction of the number of people out on a joyride as the number of people who could come onboard and have a look in a traditional open house tour.
Sure, if would be amazing to be picked for a joyride on an 056, but it makes no sense for the PLAN to do that, and ultimately, the vast majority of the people would be left disappointed as only a tiny fraction would be able to get places even if a joyride was on the cards.
Overall, it is better for the vast majority of people who wish to see the ship that they just hold a regular open house.
The only time civilians might get a ride on an 056 is if they were being rescued from either damaged ships, the sea, or a nearby foreign country in the throws of massive civil unrest. As cool as a ride on an 056 would be, I don't think you would really want to be in a position to need a ride off one in the first place.