I cannot see any picture.
But, Yes. Most trees grow their natural size leafs already when young. There are a few techniques for leaf size reduction, but they are all for mature trees. For seedlings you should let them grow. The bigger and more leafs the faster development.
Growing compact trees is done by pruning. However, I think 1,5 years from seed is way to early to start on that. Let your tree grow freely for a few years.
The bigger pot, the faster development. I tend to grow my trees in grow phase and early development phase in the biggest pots I can fit or if they are hardy, in the ground.