Convoy Special Rule "Conveyor"and Terrain Question

[Spilfair]

Hi there,

for the next Game i build my Troop for Convoy.And here is my Question,i composed a Troop where mostly Conveyor Figures are.So I can set all of the Terrain.But how will it exactly work on the Basic Terrain rules where the Limit only is until one Player said stop?Or should we in this case roll a Number of Terrain Pieces before?

On optional Terrain Rules seems much easier to do.But could I then really
60 Points(30 from my opponent and 30 Point for me)on Terrain setting?

Grettings,

Spilfair