Kaioshin
Author's note: I forgot to add this part, I should do it. Aunt Peggy received an anti-aging serum so that Tony F%$# her? This way I can make Peggy the godmother of Tony Stark and well, you know what comes next!!!" Now imagine Tony at 15 years old and his godmother who received the super soldier serum with anti-aging formula. Ready to 'Take care of Tony'.
yes im sure a 20cm increase in hight can be covered up with baggy clothes and shield will ofc not notice anything either. he could def use his skills to trade with the sorcerer supreme, eternal life without the dark dimension? just being capable of astral projection with some mind reading and if possible technopathy would really help him. pym might think himself smart but he has the key to quantum computing and matter assemblers and he uses it to become small.... heh that puts in perspective cross thinking his version is a failure for not being capable of making biomatter small. what im trying to say is the pym particle can easily be optained with magic and would make thr construction jarvis far far easier. i think you went a bit far with the AI explanation, given the available hardware it will not be a real AI anyways.