I enjoyed this and the theme and processes emerged satisfyingly as I progressed rather than crashing down as a PDM. So thanks to Kruger.
However, I have a full grid, the theme explaining 7 additions and 3 subtractions and the additional aid. However, I am one short on the changes (am I wrong to assume this is an addition?) and I am missing two misprints (the other 11 and the theme were enough to make the aid clear). The missing misprints (T and R) apparently occur in columns 4 and 8.
I enjoyed the irony of the positive addition to 9d turning one definition of the whole answer into something widely regarded as a negative in the crisis!