When setting TechnologyPrototype::max_level to an integer, while it does behave correctly in limiting the technology level to the given number and turning it green at such level, it doesn't show the level on the technology image as other infinite technologies.
I'd have expected it to show something ...

When an entity is upgraded via a bot it sends an on_robot_mined_entity event followed by an on_robot_built_entity event, so I expected the same to happen on space platforms, however that seems to not be the case as they only send an on_space_platform_mined_entity event.
I discovered this while ...

When using miners onto splitters - at high enough mining prod or mining speed - it can create gaps in the belts if the belts were partially filled, meaning belts have to be filled separately in current version to maintain two belts of throughput.
Behaviour persists regardless of speed of mining ...