A pension is safe during a PIA. However, a PIP has to do prepare a comparison showing what the outcome would be for creditors in a bankruptcy versus a PIA. if the bankruptcy outcome is better than a PIA, then the PIA may be rejected by the creditors.
As certain types of pensions can be accessed in a bankruptcy, then a bankruptcy comparison might be better etc.
One reason to go bankrupt would be to protect a future pension pot.
Jim stafford