KV7

Yeah I was half making a joke, I don't think it is an effective solution. Though it also could be cheap enough to be cost effective.

Can a cowling make much difference to the frontal aspect returns when the nozzles are already obscured by the fuselage ? You might be right that it would be desirable.

I missed something earlier, F-22 only has 2d thrust vectoring. In theory you could use an F-22 style nozzle with vertical vanes or similar to get 3d.

I think this is plausible, but Typhoon was designed to be, and is, very agile, TVC likely didn't happen because of development etc. expenses. The other consideration is that for China it is also a case of "unlocking the tech tree", if they develop an expertise in TVC it is another option for many future platforms and variants, it becomes e.g easier to add it to FC-31 etc. with some WS-19 variant, or some future unmanned platforms etc.

Sure, but the case for it depends on a cost benefit analysis, they probably reason that they get quite a bit of advantage for not much additional costs. If you think that agility is just not such a big deal, then even still TV can make sense as you can get a given agility with less use of features that are costly in terms of RCS or top speed, such a huge wings with low loading etc.

I do not think thrust vectoring is evidence of some strong desire for dogfighting ability, it is more a case of it being not very hard to do, and it also offering advantages in evasion of missiles that have lost much of their energy. I think it perhaps also can lower RCS a bit under maneuvre from the frontal aspect as you can use less control surface deflection.

Do you mean a duct like on F-22 ? It would be hard to do with 3d thrust vectoring and require a major air-frame change. An interesting question is how much they want to use J-20 as the cutting edge test bed, I think at some point they will be doing most risky developments via another project. J-20A I think is going to go into quite serious volume production, this is seemingly indicated by the scaling back of production plans for older models.

Is there 5.45 mm ratshot ?

Capitalism is more than markets and private property, it canonically also features capitalist class political and economic hegemony. A market mixed economy with a capitalist sector that is incentivised to develop the nation etc. and which cannot case strife through some capital strike etc. is desirable, and it was partially achieved in parts of the west in the post war period but for this to be stable it, it would then not be capitalism, if it capitalist it will be unstable because the capitalist class can and likely will at some stage tire of the restrictions, and if politically hegemonic, will succeed.

This is very interesting too, though as above add grains of salt as it is an amateur (but quite careful and well done) analysis: It is odd that Su-57 seemingly has such a strong optimisation for stealth in VHF. https://basicsaboutaerodynamicsandavionics.wordpress.com/2023/01/15/f-35-vs-j-20-vs-su-57-radar-scattering-simulation-summary/

This has been well discussed, and now even modeled.

J-20A with WS-15

The argument in the OP discussion is not that 155 is better than 152mm, but that 155mm systems are more available on the export market, then by adopting 155mm alongside 152mm, they can cover any shortfalls with imports. AH-2 is Chinese, though a development of GH N-45 with a longer barrel. China also already has 152 and 155mm guns in service.

20km is not near the limit of what can be done. Polyphem (though cancelled) and ALAS are in the ~60km class. Type 96 and basic FOG-MPM is more like 25 km or so, there apparently is some ER FOG-MPM variant with closer to 60km range.

In theory can go up to 100km or at a stretch a bit more or so before you need a repeater. But before such distances are reached, the spool will be massive and the cable will be at high risk of breaking.