Ann: Becoming a substantial holder, page-13

that's correct, I couldn't find any specific 'block out' periods in their policy...but to avoid looking suspicious I don't think Directors would be buying 1 week b4 big announcement, therefore my thinking is anytime from next week onwards, furthermore they will defend any potential inquiries with the fact that MNS has released an official ASX ann (16.08.18) stating:

..."Further to the corporate update made on 25 July 2018, discussions have progressed with multiple groups who are currently undertaking either technical or legal due diligence, with the view of making an investment in the Company. Indications to date point to an investment decision in Magnis being made by the end of the month. Several of the potential investors being considered would be either cornerstone or strategic investors.

In addition, during the past months, the Company has fielded interest from potential joint venture partners for Nachu. Plans are being made for site visits in the current quarter with at least two of these parties. The Company will provide further details as they come to hand"...