During Napoleónicas wars the English purchased their food from Morocco.Very interesting TL. I'm following this from now on.
Just a suggestion: throughout most of Modern Era Portugal wasn't able to feed itself and was dependent on wheat imports. You incorporated Spanish areas mostly related to cattle and sheep herding, so, I think that problem will persist. IMHO the best geopolitical choice to have a cheap source of grain is to occupy and/or have a special relationship with Morocco somewhere along the way, as I think it would be complicated to depend on Spain or any other European nation for grain.
So it makes sense that Morocco becomes Portugal’s breadbasket. To accomplish that realistically could be as follows.
During the 16th century you could have Portugal increase its imprint in North Africa by conquering all the coast north of Mazagao make kingdom of Fez a vassal of Portugal and it plus Portuguese North Africa becomes Portugal’s breadbasket.
integration of fez and even conquest or Maraquez could happen in the 17th century.