I would have grave reservations about IVA and there are definitely a lot of people seriously misrepresenting what can, or can't be achieved.
However a friend of mine had a tax problem a while ago and it was an answer. Essentially HMRC were threatening immediate proceedings for a sum which he didn't have, but could raise given time. I don't have any opinion on how he allowed this situation to develop.
Essentially he obtained and IVA on the basis that he would pay a certain amount at a certain date, and payments thereafter. On that basis he maintained control of how he liquidated his assets ( sold his house, mainly ) and certainly got a better deal than would otherwise have been achieved.
''the stopes soared beyond the range of our caplamps' - David Bick...... How times change .... oh, I don't know, I've still got a lamp like that.