Ukraine

This thing they call "off budget funding scheme" is actually a mechanism Russia has used for many years way before the invasion of Ukraine.

Basically Russia allow the military industrial complex to export weapons for profit. This helps finance development and allow the Russian government to purchase equipment at prices they basically dictate themselves, generally at a loss to manufacturers. So exports are required to keep the system going.

After the Invasion exports have plummeted, in part because Russia use everything themselves, and in part because Russian equipment was exposed as not being as good as advertised. This has caused huge deficits in Russian weapons industry, so they have had to borrow to cover their expenses.

This fact has been covered many places already, where weapons industry normally benefit from increased budgets of war, that is not the case in Russia.
I suppose it can be seen as an "off budget funding scheme", where Russia is actually undermining their own defense industry.

This is opposite Ukraine that has a more traditional approach, and probably the reason we see more innovation from Ukraine than from the 3-4 times richer and more populous Russia.

It's not that the article is wrong per se, the observation is correct, but it is taken from a different indirect angle/perspective than the usual. But absolutely, the debt build-up and lack of profits in the Russian military industrial complex will be a huge problem, that the government will need to solve somehow and soon. Either cover the debts, or accept to lose most of their military industry in a future not too far away.

It can absolutely also be said that this scheme hides the real cost to the Russian economy. I think that's probably the best and most important point of the article. The war is actually way more expensive than it seems from the official budgets.
And I'm pretty sure Russian military industry will never quite recover to its former "glory" before the war with Ukraine.