OCCUPYING BEFORE SETTLEMENT

I recently deposited 5% on vacant housewith standard 28-day settlement.
Valuer said he needs Building report which has stalled it all and reduces prospects of an earlier settlment which I HAD HOPED FOR AS NEED to move ASAP.
Anyone know of whether earlier occupation of house-if insured etc by me would entertained.
Even if just for 2 weeks at above market rent.
After all it would be a win-win.
I should have building report give all-clear tomorrow.
Also valuers- are they obliged to value given “existing use” or adopt the more realistic future use or “highest possible use”. This is Council-approved as a 2-lot site. Now if ultimately site is redeveloped ie origijnal house demolished and 2 dwellings built the rent is greater. Valuer knew this but just valued it as a house on larger than normal block. Therefore in my view he undervalued it.
Any advise and any way to convince VALUER or lender to reassess the value. Refer to Michael Masutik (i think) piece in weekend AFR RE DETACHED DWELLINGS ON Large blocks with possible redevelopment.