In stating that SCG are able to unilaterally increase their...

In stating that SCG are able to unilaterally increase their management service fee from 0.6% to 2% you seem to be asserting that the "Related Party Disclosure" that you have quoted is the sole and only reference for that fee between the parties. I would be surprised if that is the case.

While the quote mentions the ability of the RE to set the fee I would fully expect that there are supporting agreements and annual reviews that ensure that the Trust is receiving value for money and that such detailed agreements would not generally be disclosed. It may be that the $5m annual fee is already profitable and the Trustees have a degree of leverage in the matter which introduces practical limitations on what SCG is able to charge.

All conjecture on my behalf but simply pointing out that if it was as simple as saying "pay the full 2% thanks" as you suggest it begs the question as to why they didn't do it from inception.