There are lots of things aside from poles and signals a user might want to have farl replicate: lights, turrets, radar, roboports...
Two ideas:
- A simple incremental repeat value for everything in the blueprint (possibly with options for signal/rail to include/exclude those),
- Let the user lay things out in the blueprint. Thus, if the blueprint is more than 2 rows high, you can basically modulo the position as you go. That would even let people tackle things like largely single-line rails with branches.