Welcome to the forum @samefi I have never toyed with the newer stuff and know very little about the old OBD! systems. I played some with mine but didn't get too far with it. There are others here who know lots more than I do but I will caution you on it a little. Lots of experienced folks kinda shy away from it or talk about it much especially on the newer stuff mainly because of what gobment (misspelled intentionally) has done to others. it's hard to find folks that are willing get into the details too much because of that.
I guess it all depends on your location and what you can technically get away with keeping it street legal to pass inspections and emissions testing.
I know knottt one thing about ECMs or even how them black boxes fuction, welcome to the forum.
EPA has really crashed down on anyone messing with ECMs so it is rare to find anyone willing to talk about ECMs over an open forum. Face to face might be a different story but in My mind I think anyone thats a member in this forum will not talk about programming ECMs.
Please do though, post us in some pics of Your truck. We’d love to see those and discuss any other matters with it.