Linetype with Multiple Lines?

I’d like to be able to have a single line, when on a specific layer, print as a solid line with a dashed line a specific distance away from it (see screenshot below). I know that I could offset the first line and have a dashed and a solid line, but I was hoping there could be a more elegant way to manage these lines.

Imagine having hundreds of these lines where the dashed like is 1/8" away from the solid line and needing to change it to be 3/16" away. Lots of work. I understand that I could finagle it with record history, but then blocks don’t work. Understood that Rhino is not parametric, but was hoping

I don’t think it’s possible in the existing linetype system, a hatch would make this more complicated, not less complicated, record history doesn’t work with blocks, grasshopper could find lines on layers and offset them, but that means re-running the grasshopper script periodically.

I feel like maybe a display style could do this?

Would really appreciate any ideas from rhino wizards on this.

This is not currently possible in Rhino, but has been on the wishlist for a while and in general is something I hope to figure out in Rhino 9. We’ve made a ton of linetype enhancements in Rhino 8 and these changes set a foundation for further enhancements like this in the future.

Thank you for the thoughtful reply, Steve. I think this would be a great item to make Rhino a more flexible drawing tool.

All the best,
Alec