Currently, I am in a cut. I try not to overeat. Eating enough protein and more than TDEE-500kcal. Sometimes my calorie deficit is larger than 500kcal, especially if I go cycling or hiking. On those days, I simply add another protein rich meal consisting of Tofu and some vegetables, just to get enough calories out of fear to lose muscles. Do I have to do that?

When is an aggressive cut good? Only if you need to get to a certain weight for a competition?

I can not find any primary or reputable source, only blog posts about it.

Edit: this sounds good https://macrofactor.com/cutting-calculator/

With energy deficits smaller than about 500 Calories per day (which would equate to losing about 1 pound or 0.5kg per week), subjects (on average) were able to experience a bit of body recomposition (losing fat, while gaining a little muscle). With deficits larger than 500 Calories per day, subjects tended to lose lean mass, with the rate of lean mass loss increasing as energy deficits grew

Meaning, avoiding an aggressive cut is advisable if you don't have to get below a certain weight