All Chinese loans are sustainable. Chinese to the maths before sending their contractors down here.
So as long as we borrow from China, that can be kept off the books and all will be well.
The problem is that the "good" Chinese loans get added up to the books anyway and that raises the ratio high any way.
As in the Argentina case or the ongoing Venezuela saga, once a country defaults the effects are the same regardless of which loans are "good". Venezuela may get a pass and avoid punitive interests from China (not that it is confirmed) but the other creditors have reacted anyway. I doubt that those who lent us the Eurobond will sleep easy knowing that we are unable to service the Chinese debt. And any way once you default it doesn't matter who is good or not, does it?
These debts are maturing soon.
Any way, I note that you are unable or unwilling to state what percentage is sustainable.
You can have mine: The moment they hit 40% it had gone too far.