Strata title block of units

Could you advise how long it would take and how costly it might be to strata a block of 6 units in regional NSW? Has this been successful for anyone? I am looking to split up and sell on some of the block and keep some for rental investment.
Key issue is fire-proofing the walls between the units. This may be costly and a lengthy exercise and only a building surveyor could tell you that information.
Also be aware of SEPP rules which may prevent conversion of affordable housing

And the other obvious one, most lenders will look at this purchase as a comm transaction,so your holding costs and deposit requirements may be much higher than you perceive