I can see how not saving paths would be a pain, especially if they're used as an integral part of a building (e.g. flooring in a shopping area). I would hope it's something that Frontier can add to the game without too much effort.
I'd also love to see terrain added. Not everyone is a sculpting master, and many of the parks that Frontier have shared use sculpted terrain in some way as an embellishment. It seems a shame that you can only save off your park as a whole. Using terrain as an integral part of a ride (with scenery) implies that you can't select and save that ride as a whole, which diminishes the blueprint feature. Having said that, I can see how it would be a tricky thing to get right, not least because the tools for adequate selection of a section of terrain don't exist. In its most basic form, a cuboid surrounding the terrain you want to export might work, but a more complete solution might involve painting the areas of the terrain that you're interested in.
Add to that the complexity of applying the terrain to an existing park (do you store it as deltas from a baseline level? do you allow vertical displacement of the blueprinted terrain? etc.) I don't think we'll see it any time soon. [ Frontier: do feel free to prove me wrong...
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