there really are no economic or industrial limitaions to how many DDGs China wants, the only deciding factor is the will of the CCP (ie: if they want more DDGs they will build more DDGs, if they want less they will build less) if anything China suffering from an economic trouble causing it to significantly reduce the DDG production is nothing more than a fantasy & wishfull thinking from China haters , they have a similar mentality to the likes of Gordon Chang & David Axe, it's similar to what some Indians think when talking about the PLAN build up just to assure themselves everything will work itself "we don't need to worry about them, the PLAN doesn't have experience, they don't have crews, quality is bad, they cant maintain ships blah blah blah.." I'm not saying that China will keep on producing 10 DDGs per year for ever, may be they would or may be they wouldn't who knows! may be after 2-4 years from now DDG production will be lowered back to 5 per year, I'm not Xi Jinping so I don't know how many DDGs the PLAN wants, but in any case the number of DDGs that have been produced in 2019 was undoubtibly a surge, in many cases a surge in weapons' production is done when a country is preparing for war that it knows will happen or intends to wage one (Taiwan sepratists better say their prayers), once the Taiwan issue is resolved then China may decide that it's pointless to maintain a huge DDG fleet & may bring down the DDG production rate to 3 or 4 per year, or may they wouldn't! it totally depends on how hawkish (or peacefull) China will be in the future.
China's strategy is peaceful economic development, as evidenced by 20+ years of military spending at 2% of GDP.
But we've seen a rapid increase in DDG construction over the past 2 years, from an average of 3 per year to 10 per year.
This coincides with China being cast as the enemy by the US and a quasi-containment policy being waged.
So I really see China's future level of military spending being dependent on how the US acts.
If things do get worse, I reckon that China would build 10 DDG per year for the next 5 years.
That means the modern DDG fleet grows from 40 to 90 ships. Then they could drop down to a sustainable level of 6 DDG per year, which eventually means a fleet of 200.
But like i say, this is only if US-China relations get worse.