Thanks everyone. Most of those planks are 1/2", some are 3/4" thick. I’ll experiment with some throw-away pieces to see how it behaves. This wood is really dry, so I don’t think there will be much residue but I don’t know what I’m talking about lol.
I might cut some of those in 1/2 to make it go further; I would just need to distress the wood on the ends where I cut it. Woodcraft sells this stuff that distresses wood (basically just rots it and dyes it at the same time) that I may try on the ends.
I figured I would just stay far far away from pressure-treated/borite-treated framing lumber. Home Depot sells cedar “dogear” fencing pieces that are very inexpensive that I may play with. They’re not treated so it should be ok.
I have the Pro model coming, so the 20" limit is one I can work around.