Good Suggestions -- Implemented!
1: Balancing Belt Type. Close, but the internals aren't turbo belts: the balancer's internal belts ran at a fixed 0.25 tiles per tick, which is twice a turbo belt, so nothing in the base game or Space Age could outrun them. You were right about modded belts though — anything faster than 120 items per second per port would have been silently throttled. As of this update that speed is a floor instead of a constant: at the end of the data stage the mod reads every belt, underground, splitter, lane splitter, loader and linked belt your mods define, and gives its internal belts the fastest speed among them. Install a faster belt and the balancer keeps up with it.
2: Recipe cost. There's a new startup setting, Balancer part recipe, with six options: the original 4 plates / 2 gears / 2 belts, a cheaper 2 plates / 1 belt, versions using fast or express belts, and two splitter-based ones (a splitter plus plates, or an express splitter plus steel).
3: Technology requirement. A second startup setting, Balancer research cost, picks whether the balancer unlocks at Logistics, Logistics 2, or Logistics 3. The cost is read off the chosen technology rather than hardcoded, so it charges whatever your modpack charges for that tier — and the prerequisite moves with it, so the research sits beside its own tier in the tree instead of being reachable long before you can afford it.
Both settings default to exactly the old behavior, so updating an existing save changes nothing until you opt in.
