Tax liabilities owed at the debt of adjudication are written off in a bankruptcy. However, there is one possible exception to this, and that is where the tax debts arise from fraud.
It might be possible to deal with tax debts in a DSA/PIA. However, the Revenue are very "firm and tough" in considering such cases. It can take a lot of persuasion to get Revenue to participate in DSAs/PIAs. The Revenue's preferential status as a creditor in a bankruptcy can present a high threshold to overcome in persuading them to participate in a DSA/PIA.
Jim Stafford