Then I would have to disagree on the technology and subsystems front. With CV-16, China had a more or less complete hull - sandblast the rust off, put the boilers in, hook the radars up and away we go. I'd say CV-16 to CV-17 was bigger since China had to start from the keel up. CV-17 to 003 was the biggest of all since it was both a new design with an entirely new launching system. 003 and CVN would be a smaller jump since all of the subsystems, with the exception of the powerplant*, will either be the same (up to scaling) or will be descended from 003's systems. I consider 003 to be China's first "true" carrier and the riskiest and most difficult ship on its naval modernization path.
* The nuclear reactors would not be entirely novel since China has extensive experience fielding similar powerplants on submarines. Experience with things like shielding the crew from the radiation would be readily applicable.
You just said so yourself -- "a more or less complete hull".
Constructing the hull of a ship, even for a ship as big as a carrier, is the easier part of building a ship. Fitting a ship out with the subsystems is the harder part -- and it is even more challenging if the subsystems are ones that you have to source domestically, and for a new ship type that you've never had experience before, like a carrier in the case of the PLAN and CV-16.
(Just look at the amount of time taken for many nations to fit out ships after launch -- the less competent examples like Indian and Russian shipbuilding examples for their frigates, destroyers and carriers is a great reflection of just why fitting out is arguably more challenging than the process of building the hull itself).
Furthermore, the differences between a relatively large STOBAR carrier like CV-16/17 and a large CATOBAR carrier like 003 is primarily the EM catapults.
If we exclude the EM catapults, other subsystems such as arresting gear, optical landing system, flight control/tracking system, capital ship threshold battle management system/CIC, munitions management, are all very important technologies that had to be verified on CV-16 first, which they had no prior application on a ship of that size or type before.
Meanwhile, for 003, all of those carrier specific subsystems will be mature (and likely be evolved iterations of them) -- but the only significant technology introduced on 003 from CV-16/17 is its EM catapults.
To put it into a more condensed way:
New technologies demonstrated/needed between "nothing" and CV-16: arresting gear, optical landing system, flight control/tracking system, capital ship threshold battle management system/CIC, munitions management
New technologies demonstrated/needed between CV-17 and 003: basically just EM catapults