I stand corrected. I was basing it on being told multiple times you should never burn pine in a fireplace because it leaves “tar” up the chimney that can catch fire.
That’s probably a good idea if you’re going to be using the filter.
This graphic is from the FAQ on Glowforge.com, and uses 11 minute cuts as the control:
You can see the lowest is medium ply, since it uses a draftboard core. Sometime back, the thick plywood switched to some other type of core.
But, 175 eleven minute cuts in medium ply equates to ~32 hours of use before the filter is full. I can only imagine that the thick draftboard would be even quicker to fill it.
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Hey, that’s a nice little chart…hadn’t seen that yet! 
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Thanks for the further explanation. I was trying to figure out the huge discrepancy between medium and thick PG plywood!
Back in the days when I had a fireplace I had fatwood pine that was very full of resin and oak that was harder to light but burned hotter and longer. I would not try to laser Fatwood (longleaf) pine but getting a hot fire going quickly in the fireplace it worked well and being 2/3 oak that went on for hours after the other was gone, and did not have a problem.
I see you already emailed us about this and we’re working on it there, so I’m going to close this topic.