During a bulking phase characterized by a hypercaloric and high-carbohydrate diet, which peptides and/or supplements could be taken to minimize fat accumulation?
We can only speculate about this in theory, but in practice, no peptide is really going to help you because peptides don't burn energy themselves. They only create conditions that make it easier for your body to use fat as an energy source. But when you're in a calorie surplus, this effect will be almost completely offset by the accumulation of new fat from food. Basically, you'd be pouring water into a leaking bucket.
For example, growth hormone has a significant lipolytic effect. This means it increases the use of fatty acids from fat tissue as fuel. So, theoretically, with the same calorie surplus, you might expect slightly less fat accumulation.
However, there's an important detail when it comes to high-carb bulking. Growth hormone can reduce insulin sensitivity, increase glucose production in the liver, and raise blood glucose and insulin levels. So combining a large calorie surplus, high carbohydrate intake, and growth hormone isn't particularly beneficial in the long run.
Also, don't confuse lipolysis with being unable to gain fat. If your calorie surplus is large enough, you'll still store fat. Growth hormone may change how your body distributes nutrients and uses fat, but it doesn't override the laws of energy balance.
Overall, you'll either get no benefit at all or the benefit will be so small that you won't even notice it.
My recommendation is to keep your calorie surplus at a level where you gain little to no unnecessary fat. That's not so easy to achieve because it requires you to carefully analyze what you eat and how intensely you train to find that balance point.
But using growth hormone for this purpose would be a waste of money.