Issue description
When placing the longest transport you can in one go, you can see that the last two pillars are much closer than the others:

And since clicking places a pillar, this repeats on longer segments:

To fix this, you need to manually place the pillar at the second last spot, and repeat that every transport-length:

Notice how nicely spaced the pillars are?
My suggestion would be either to reduce the length of the transport you can place by 5 blocks, or increase it by 4 blocks. Alternatively, don't place a pillar on the end if it's too close to the previous pillar unless it's to finalize placement. This seems more confusing though.
Reproduction steps
See above
Game version and build number
Update 1 0.5.3d (224)
Operating system
Windows