Ann: Trading Halt, page-18

Apparently it says the offer is irrevocable once paid so doesn't look like you can from the info I was provided. You could call Computershare to check I guess.

But they don't have any control if you chose to sell some current holdings on market do they? Would that be an option for you? Maybe seek some financial advice whether that is a viable option?

I have done this myself before in spp offers. It's not a bad way to help fund the company without increasing exposure IMO. It's obviously better if you can sell at spp price or higher though.