Oh jd lol. Almost, almost.
I have no idea what cap is in it now, but I took it to a shop, they had a replacement for it and said the board was good still after cleaning off the leakage. He soldered the new one on for me.
So I got it back together and everything's running perfectly. I ran out of time yesterday but I still need to check for codes to be sure. But it drove like it was back to normal.
I appreciate everyone's input, I pretty much tested everything I could test til I figured out it was the ecm. And shout-out to jd for helping along the way outside of this thread.