but I have the impression that they made some additional changes besides just increasing the max debt ratio.

Yes, they have definitely made changes. I have seen that the start and stop thresholds are now 20% there. So there is no longer an intermediate range. However, I do not know whether there are any further changes in relation to economic aspects.

By lowering the 80% threshold, it would move the reduction percentage to the right on the curve, which just means that the virtual_supply would be less sensitive to future price changes.

Ah, yes, I see.

It might actually be useful to think about implementing that.

I think too. That's something I would shortlist for a hardfork.