The defining thing about the made-to-order convenience hoagie is that the eater designs it, not the kitchen, and the build is the negotiation between that freedom and a roll that has to survive it. An Italian deli hoagie is ordered component by component from a screen: the roll, the meats, the cheese, the vegetables, the oil and vinegar and seasoning, each chosen by the person eating it. The sandwich is assembled fast against that spec, which means the structural rules have to hold no matter how the order is configured. The roll is the fixed constraint; everything layered into it is variable.
The craft is in the layering and the dress, the same logic every long-roll sandwich runs on. The roll is split and built the full length so every bite carries the whole sandwich rather than hitting a pocket of one thing. Cured meats and cheese are shingled, overlapped in thin folded layers rather than stacked in slabs, so the load compresses evenly and each bite gets all of them. Lettuce, tomato, and onion go on as the cool, acidic, crunchy counter, and oil, vinegar, and a dried oregano-and-pepper seasoning are applied as a system that lubricates and seasons without soaking the crumb. The roll has to have enough crust to hold a heavy, wet, variable load without folding in the middle and a tender enough interior not to fight the filling, because the eater can make the load as heavy as they want and the bread still has to carry it.
The variations are built into the format itself: the same architecture runs cold with Italian meats, with turkey, with ham, or meatless with extra vegetables and cheese, and the hot builds turn the roll into a vessel for a sauced filling. Each is a codified build with its own balance of meat, acid, and bread, and each belongs to the wider sub, hoagie, hero, and grinder family rather than being crowded in here.