I specifically dislike that the belts are self-powered, almost every other automated system requires a power source of some kind; but I also dislike the idea of needing to cover every last inch of transport belt with power line coverage.
My suggestion would be to replace the tiers of transport belts with a single belt type, but then move the tier concept over to a new device that powers the belt, like a "belt motor". The belt motors could be of different types (think along the lines of the existing burner/electric structures) and offer different ranges (so you could have a burner motor, a long distance motor, a high speed motor, etc.) and accept modules and the like. I figure the distance would be calculated in a manner similar to that of hot water being pumped through steam engines. The motor itself could either resemble a belt tile, or sit parallel to the belt. For the sake of not overcomplicating it, belts would still have their own directions, they'd only require adjacency within the distance limit to receive power, assume some clever gearing.
The intended effects:
- The automated belts would now have the same behaviors and requirements as all the other automated systems.
- The belt upgrade process is now centralized to a handful of motors instead of tile by tile in your belt system.
- Trains become slightly more attractive for efficient long distance cargo hauling.