I build long belts... and I like it :) even if this is bothersome and little tricky.
When I try to lay it with nice curve and place it and adjust conveyor pole stackable just a little, at the end, belts wriggle at poles.
Same with the train rails as developers shows. They can be nice curved and stright, but often they can twist that you even don't suspect.
Now idea - vehicles can record path (feature already in game). This path are much more smooth that player can plan step by step. We can use it and with supply, vehicle can place desired belt or rail layout automaticly with IMHO better visual effect.