So I went to Home Depot several months ago to pick up some plywood for cutting on the laser decided to try out some sandply. It's cheaper than birch or oak, lighter, and seems to be less prone to warping, which is pretty important when laser cutting. Given that sandply is less dense than the bitch I had been cutting, I expected the laser to cut through it without issue. When I tried it out on the same settings I had been using for birch and I was not impressed.
Above you can see that some parts continued to burn after the laser cut through the wood (air asset doesn't seem to have an effect on this charring) and below you can see that the laser just barely failed to go all the way trough several parts at the same laser settings used for birch. I haven't tried to see if I can elevate the issues I was seeing, but I'd say that sandply is probably not a go to material for laser cutting functional wood parts.