What is supposedly going into production is the system- the launchers, radars, command centers. They don't even have a missile yet- the S-500 uses the same missiles as S-300v(x)/S-400.
I hope they work better than the S-300's on the Moskva, lol.
The reason the S-400 caused a problem with Turkey is the IFF issue and potential range profiling of NATO aircraft. That's why Turkey was dropped from the F-35, and may lose their license for F-16 production/depot work.
Russia has a limited supply of modern missiles- Kalibr and Iskander, and they have been expending them at a good clip. There is a clip of them hitting a Grad with an Iskander. That is a stupid use of that weapon, the missile was worth more than the target. Kalibrs are fired at apartment buildings, same thing- a high-end weapon used on a non-strategic target- not an intelligent use of resources.
The DOD assessment is that they have spent 70% of their available PGM inventory in Ukraine. They started with 160 Iskanders- 13 brigades with 12 missiles and one brigade with 4. (according to the Wiki page).
Russia can't replace these missiles at the rate they are using them, and if they expend them in Ukraine they have nothing left for a conflict with NATO or China.
Both missiles use components sourced from western countries- fiberoptic gyros from the UK, circuit boards, heat shields and connectors from the US, chips from Taiwan and Japan. They will have to redesign these systems around Chinese components, and that will require a lot of redesign and testing.
There is also the question of how much help the Chinese will really want to provide. Chinese arms suppliers are in direct competition with Russian arms suppliers for the same customers. Those countries are watching the Russian systems poor performance in Ukraine, and may be having second thoughts.
Hell, China is also dependent on Taiwan and Japan for chips, and that supply might get cut off if they get diverted to Russia.
India cancelled a tender for 48 MI-17's after the invasion, and they took special note of the SU-35S shootdown. Go to Bharat-Rakshak and read how Indian defense professionals are talking about their dependence on Russian systems. They are not very complimentary...