There is an argument in favour. Consider what happens at present.
1) You want to buy a house and you need a mortgage.
2) The building society recently turned bank says "we'll need a valuation and you're paying".
3) They send round their approved expert who, for a fat fee, looks it up and down then gives the OK.
4) Your plans fall through and you have to drop out.
5) Somebody else who wants to buy the house goes to the same bank.
6) They say "we'll need a valuation and you're paying".
7) They call their approved expert who, for a fat fee, prints off a copy of the valuation he's already done.
8.) Their plans also fall through so a third mug goes to the bank for a mortgage ---
There's a certain logic in doing all this stuff just once and adding the cost to the selling price. The devil is of course in the detail. The info pack will be a complete waste of time and money if the banks refuse to accept it.