Regarding economic sabotage, it was probably part of the plan,...

Regarding economic sabotage, it was probably part of the plan, starting with creating a cover excuse of deliberately depriving themselves under cover of no coal since their reaction to Australia's modest request for Covid background never made sense. Now it may be a bit far fetched but an excellent plan poorly executed is always better than a bad plan well executed i.e. our dear leader may have gone off the rails in places and his plan for eternal deification has hit some speed bumps. But no matter. Their time line might have suffered a few kinks and items brought forward, but if you have a definite goal insight it is only a matter of juggling. Then there is this:

At the beginning of the war, the British and French placed large orders for aircraft with American manufacturers and the US Congress approved plans to increase its air forces by 3,000 planes. In May 1940, Franklin D. Roosevelt called for the production of 185,000 aeroplanes, 120,000 tanks, 55,000 anti-aircraft guns and 18 million tons of merchant shipping in two years. Adolf Hitler was told by his advisors that this was American propaganda; in 1939, annual aircraft production for the US military was less than 3,000 planes.

So where there is will and money ..don't be surprised.Throw a couple or three billion dollars at the German Industrial base, just for starters and there is no reason seriously sized plants could not be up and running in six months. How do I know? If the Chinese can throw up hospitals in a few weeks and USA can build mega economy in two years a few magnesium plants has to be a cinch. In a few places around the light of candles someone is coming up with a solution for sure, don't expect to read about in the papers before hand.

If if is Germany, their excuse is simple, "Dear China, you have some electricity/magnesium problems. Don't worry we are here to help out."
China will never get its magnesium market back except for internal consumption and likely more expensive. Look out for bouts of economic espionage as their Pigeon Process is out dated i.e. their whole industry. The excellent news for China is their electricity supply could be fully sorted mid next year. Win-win. Now that's a plan.