the work could progress with the formula as follows; a valuation of a completed 2 bedroom apartment, minus the cost of the building work, with the residue of value to be split with 50% going to the body corporate for repairs etc. while I received a 50% discount on the money I paid to the BC for using my initiative.
And there’s your issue. The formula established in a Supreme Court ruling was that the owners corp would be compensated on the basis of A-(B+C) where A = the estimated value of the improved property; B = the estimated current value of the property and C = the cost of the improvements, including the legal paperwork and plans.
The benefit of your initiative would be accrued as the value of your property grew over time. The “crusty old solicitor” may have just been following established law and precedent.
I would go back to your committee with a renewed proposal based on the above principle but without the “initiative” reward. If they refuse, wait a year and try again under the new laws under which they would have to explain their decisions for refusal.