How should Chinese citizens go about returning to China?

Due to the covid-19 pandemic, flying (from Germany, but presumably also from other countries) to China is a bit complicated these days:

• The Chinese transportation authority only allows one flight per week per airline per country of origin. Thus, there is currently a total of eight direct flights from Germany to China per month.
• In addition, airlines are penalized for importing covid-19 cases. If too many passengers turn out to be covid-19-positive, the respective airline will be banned from conducting flights from that destination for a month.
• A few foreign airlines start getting permits to conduct flights to China again. From Germany, this would be Lufthansa. However, at least according to reports circulated on Chinese social media, already the very first flight, in June, was overbooked, leaving some passengers stranded in Frankfurt airport without a visa to enter anywhere other than China, and with Lufthansa offering them to either get a refund for their ticket or get one of the next available seats in September.
• Of the relatively little capacity for passengers to travel from Germany to China that is available, quite some is used up by Chinese nationals who use the connection from Germany to China as the second leg on their attempted return from the U.S.

As a result, many Chinese citizens are stranded abroad - such as my Chinese in-laws, who have arrived in January on their 90-days Schengen visa and are still here now, in July, with no idea how or when they can return.

They are on Air China's waiting list (somewhere beyond position 200, which has barely changed during the past couple of weeks), and will have to pay the difference to their original fare (for the originally planned, but cancelled return flight) once there are any free seats.

For now, they should be fine visa-wise until the end of September, though their prolonged Schengen visa is only valid for Germany, thus travelling from another Schengen country is not an option. Likewise, they only speak Chinese, so they cannot change flights anywhere outside of China on their own as they'd be totally lost.

What is a practical way for them to proceed?

• Rely on the waiting list, even though it may mean they have to stay for several more months.
• Book tickets with various airlines, hoping that one such connection will actually end up flying. Of course, this means spending four-digit sums of Euros and possibly not getting back some of it, or at least only a few months later.

Is there anything they can do to increase their chances of speeding up their return? Or, conversely, is there anything they should avoid doing, so, if they cannot leave Germany before the prolonged visa phase eventually ends, they cannot be accused of "not trying hard enough"?