It is very difficult to work out the net changes to the lease...

It is very difficult to work out the net changes to the lease liabilities.
I assume:
-some leases will have rent increases baked in
- more negotiating power on short duration leases (20% of floor space)
- the other long leases either good assets or impaired already
- total lease liabilities and net rental expense coming down
- some costs increasing without rent waivers etc from the Covid period (H120 was ~50m)

This can be sense checked with the net liability (current and non-current) coming down as well as the net rental expenses trending down from a peak of about 230m in 2017.

The 40% MoM increase Nov to October is normal seasonality. I think -10% is the absolute floor based on David Jones reported figures, and they are also working on a similarly reduced inventory position as Myer FY20. My guess is it will actually be up a few percent but I really have no basis for it apart from conjecture.

But apart from the zero abnormals I know that my assumptions are conservative with the known information. I think there is sufficient margin of safety.