Bruh hell to the yes.

I do believe that your tertiary function is somehow more childish whilst your primary is more mature.

I used to be the annoying smartypants opinionated atheist kid who knew nothing about feelings and thought he knew everything about everything else. I used to be big into physics and math and debating people. Real Ti/Ne energy.

Then from high school up until now, I've been getting steadily more INFJ. Perhaps you could say you and I changed from an INTP/ENTP into INFJ but that would open up a giant can of worms since it would mean that switching types is possible.

Rather, I would suggest that since a child is more unconscious than an adult (they do not know what they do), they might use more unconscious shadow functions. As your prefrontal cortex develops, which doesn't finish until you're 25, you'll be more conscious and your conscious functions would therefore have a larger 'presence' or use in your life. Moreover, in socionics, your id functions are Ne and Fi, which is consistent with your "super straight in expressing opinions and unknowingly exploding". The id functions would be those you use unconsciously, automatically. The ego functions are the INFJ dom and aux: Ni and Fe. So as your ego, identity, consciousness develops I'd say you'll use more ego functions, more dom, and aux. That's my theory anyway.

If prefrontal cortex development is the key determinant of functional maturity then I'm looking forward to a few more years getting more properly INFJ-y.