@Cosmoclarke - Good question, I did some research on this point....

@Cosmoclarke - Good question, I did some research on this point. Answer = I don't think it would be in their interest to purchase shares (either on or off market). Why: The bidder and its associates cannot vote on the scheme of arrangement.

Supporting source material:
1. "For a scheme of arrangement to be approved by the court it must have been approved by a majority in number of shareholders present and voting (unless the court orders otherwise), and by 75% of the votes cast at the scheme meeting. The bidder and its associates usually cannot or would not vote."
https://www.ashurst.com/en/news-and-insights/legal-updates/takeovers-in-australia/#:~:text=For%20a%20scheme%20of%20arrangement,cannot%20or%20would%20not%20vote

2. "A bidder in a scheme of arrangement cannot vote its own shares, and so a pre-bid holding may be counter-productive to the success of a scheme..." Takeovers Guide Australia 2020 - Baker McKenzie (pg 19: PDF doc, so cant paste link )