Well, well, well...
Congrats on the "promotion" but maybe you need to let go of past butt-hurts and rise to your new status?
While I am of course a massive supporter of the Turkish defence industry, I do not have that inbuilt Turkish national that would cloud my judgement and think Turkey could get to within 10-20 years of US/Chinese fighter engine tech by the 2030s.
Of course I would love to see BAF flying a few squadrons of KAANs in the 2030s, and even with an interim 4+ generation engine with circa 140kN Engine, it would still be a good fighter aircraft for BD, when flying alongside more squadrons of J-31.
It doesn't take 20 years to develop a Turbo fan. And especially not with the amount of experience Turkey has with License producing the GE F110 in Turkey itself.
Here are a few reasons as to why I think the China issue isn't comparable.
China started from Absolute scratch in building out its Turbofans. Turkey(Tusas/TEI) is not starting from Scratch. Turkey got its start in engine development by being chosen as a component manufacturer at the very beginning in the F-16 development. In this respect, the comparison for Turkey is not China, but Japan and South Korea. Which also were also F-16 partners, with the exception of GE, the only countries license producing the GE F110 engine are IHI Corporation in Japan, Samsung Techwin(now Hanwa Aerospace), and TEI in Turkey.
Now granted out of these three in terms of Engine development IHI has the most experience, followed by TEI and then Samsung/Hanwa. But regardless, all these of these started off in a better position than China(which is a credit to china considering how far they have come)
Turkey like Japan has been license producing several turbofans and turboshaft engines including the T700 and the T800 turboshafts in addition to the F110. In addition Turkey builds modules for the CFM leap and the GE9X put simply every time you take a flight on an airbus or Boeing airplane basically you are flying with engines that have modules built in Turkey.
China was given none of these privileges, China literally had to scrape the bottom of the barrel with no real tech transfers or license production of commercial engines, being under sanctions and trying to somehow figure things out by reverse engineering, espionage and trial and error.
Some people think that the only the US, UK, China and Soviet Union/Russia have been able to develop turbofans in this class, but they seem to not realize that Japan actually has a Turbofan in the same class, and it didn't take them 20 years to develop, b/c Japan like Turkey had access to tech transfer and license production experience along with being able to get access to consultants and codevelopment.
When you look at the gap between the IHI XF5 first being built out as a prototype and then compare how long it too Japan to built the first XF9 prototype you will see that it did not take 20 years. Turkey currently is at the XF5 stage of development. with the TF6000 which is undergoing testing. If you look at the similar experiences and history between IHI and TEI, its more plausible that TEI will follow the Japan timeline, not the Chinese timeline.
Right now after the TF6000, Turkey will build the TF10000 which is essentially the afterburning version of the TF60000. Loosely comparable to the way Honeywell built the F124 and then the afterburning version with the F125.
After those steps is the matter of scaling up to build the TF35000.
These steps are essentially the building blocks as described by the TEI CEO Mahmut Aksit, who used to work at GE in charge of research and development teams that worked on aircraft engines and turbines. My personal opinion I don't think he is bullshitting, he seems to have the background to know whats required for engine development. Perhaps the currently given speculative dates for delivery are optimistic, that can be reasonably argued. Me personally I haven't seen him give a date, But I certainly don't think that it will take 20 years as you suggested, given the various factors I mentioned, and this doesn't even take into account the resources that Turkey may receive from Ivchenko Progress or what is being currently negotiated with RollsRoyce. China had none of these privileges and advantages when they were building their program.