There are too many players with differing agendas. Often, it can only be observed at the margin.

As a general rule
It is “human behaviour” for all players not to want to sell anything at a loss, they will hang on until the achievable or market price returns to either a break even or a minor loss.
The visible action occurs when a participant is forced to sell because their “note holder” forces their hand and they become a distressed seller, or the position holder is required to offer up additional margin cover and is either unable or unwilling to do so and “capitulates” which is known in the trade as “puking” their assets. Highly visible.

The invisible sector will hang on if they can and will only unwind if they are tired of the discomfort, or can exit at breakeven, to live another day.
That we havent seen widespread capitulation is testament to the activities of the banks and central bankers to assist the leveraged by inflating assets back to a point that will enabled them the exit gracefully.

I find even the idea of focusing on a broad level of leverage “over and economy” to be a bit strange – we need to ask who is holding it, and what the risks are given that.

I think things like “deleveraging” are about measurable outputs for people – in truth our interest is in insuring against systemic risk, which provides and externality. However, none of this is observable, and involves fighting “unobserved counterfactuals”. People want visible progress etc etc, and so these other things get more play than they really should …

What are the incomes to support debt servicing – if these are high enough and other commitments can be met then is there really a problem?

Clearly there is no right answer as every case is different – all you can do is set out some principles or common sense ideas… prescribing a level that is ‘bad’ makes about as much sense as prescribing a level that is ‘good’.