I've reported this for U2, but I'm reporting it again to show that it's still an issue in U3.
When extending an existing transport, the new section of transport does not consider existing supports, leading to situations similar to the one depicted, where it's not possible to plug gaps in transports over buildings without deleting the entire transport and rebuilding it.
Its do to how the support system works. You can span the gap when dragging, but you cant start it with "invalid" pillar support.
It's possible to start on a tile without support as long as I extend out to a tile that can have a support. The problem occurs when there is no pillar support anywhere along the newly built segments (even though the end result would be valid, using pillars of adjacent belts).
i just built a blueprint relying on trying to get every tile out of supports and it was so frustrating with this
Check out my furnace blueprints (https://discord.com/channels/803508556325584926/1225884516216864819/1380552817626058852) and imagine my struggle
this was so frustrating
Also now that we have the ability to place and remove connectors can we get that for pillars manually too?
Oh, you're doing microchips, that's arguably worse with regard to this issue