Look at it this way, if they all default then your creditscore would be near being a big fat 0.To have some default means your score is not 0. Its a academic but lenders do look at them and decide on the credit worthness. If they want to give you that credit they can't justify it if you have 0 score.
If you on an IVA and wanted HP for washing machine, an IP would not object I think but question is whether the credit rating is high enough to get the A listed goods....so every score point counts.
And just do make the point that banks do not vote NO when they see an IVA proposal where their client may not have alerted them to any prior difficulty. They will review the proposal carefully and commercially, and make a decision as to whether this represents the best oppportunity for them to recover their debt.