Grass fed butter - any daily max?

Not sure what you mean - daily max for grass fed butter (??) or fats in general?  But I’ll take a shot at it.

Fats: the setting tabs/macros will set your fat limits so that’s a start.  But understand that, particularly at first, you may not want to hit your max limit.  Your body prefers to burn carbohydrates, so when we limit them (20-50 grams/day although everyone is different so dont be surprised if you have a different number), it forces the body to switch to an alternate source of energy: fat.  This can be either dietary fat (which we eat) or adipose fat (fat stored around the body).  

Limiting our dietary fat intake means that the body will have to burn fat stores to meet its energy requirements: it’s a zero sum game.  Limiting carb intake means it burns fat; limiting dietary fat means it burns fat stores.  Simple as that.

So if your daily fat ‘allowance’ is ‘XX’ grams, don’t look at that as a target, but a reference point.  When you’re in the ‘health improvement/weight loss’ mode, you want to stay under that; what you’re short in dietary fat is made up in burning fat stores (remember: zero sum game).  Once you meet your health/weight loss goals and switch to ‘maintenance phase’ where you eat to maintain your achievements, eating closer to your fat ‘goal’ becomes a little more important: your dietary fat is (almost) all of your energy source.

hope this helps and good luck!