You're 0 for 2.
Only if you want to be that dumb anal hot rodder who needs shit perfect.
It's pretty easy to get 6/6 stoich to lean at cruise and stoich to rich when you mat it. Same goes for every other U-flow I6 with a log manifold.
The Ford computers are great for what they are. You must be a giant fucking moron if you think they're unforgiving. They'll literally try their best to run it given whatever sensor inputs they got. Not like the GM shit that goes into limp mode if the wrong sensor goes out of spec.
They're not really easily tunable anymore though so buy a megasquirt if you want that.