Between adding water from the fruit and how dry brett will get the beer you’ll have a fairly thin beer. Adding sugar will only further thin it out. If you’re adding a dark sugar for flavor I can understand but would consider balancing any sugar addition with oats or some other body-improving grain.
[quote]The manufacturer recommends either a low mash temperature, or the addition of glucose (also known as corn sugar or dextrose) up to 5g/100 mL (5% w/v) to improve acid production.
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5g/0.1L * 4L = 200g … But as you pointed I have to balance that against preserving some body for the final beer.