It appears that MZ want IMA to sell product to them as if IMA...

It appears that MZ want IMA to sell product to them as if IMA should ignore market realities. That is, 'Why aren't you selling us what we want, given we own some of you!' The problem is that the company board and management are obliged to act in the company's best interests, and selling at a discount to market, for example, doesn't achieve this. Also, other companies may have supply level agreements, which can't be ignored to prefer MZ's needs.
MZ should realise that the inflated market price that they must bear, will come back to them in the form of a dividend, offsetting some of the higher price.

It is best if IMA and MZ can work together, acknowledging their mutual interests. The standstill and director nomination will hopefully lead to a higher shareprice and improved commercial relationship.