NEVER make extra holes, it looks very ugly and it may not be done perfectly, which will lose the aesthetic!
Most of the time, we are not exactly one size and we find ourselves in between. That's why we always recommend adjusting it to your liking, it will be much quicker, easier, and more reliable than requesting a size change... and the best part? IT WILL FIT PERFECTLY! The adjustment will be just as if we did it ourselves in the workshop, so don't worry about not wanting to keep a "fixed" belt because that's not the case.