Hi, I have a project in mind to test the pass through. (I have not used that feature yet). I would like to feed three 6’ x 12" strips of material through. The design I have would be broken in thirds to fit on the three pieces of material so that could be assembled to make a complete graphic of 6’ x 3’.
Has anyone tried anything like this? I understand there is no sw support for the passthrough feature so far. How does it work? Any advice? Thank you
Your success will depend a lot on what you’re trying to do with it. It’s be really hard to line up a massive split engrave but if you’ve got isolated vector shapes, you can probably figure out a way to cleverly register (which I think Jules is about to reply with… there’s a good post about it) and break it into different colors for stages.
You know me so well…ROFL! 
Currently you are limited to a ten inch span for your graphics, and I believe I would reduce that further to 9 inches to give a little more working room.
Then you can use something along the lines of either of these tutorials to align your material through as it feeds.
Six feet is an awfully long span to try to keep level - you’ll need to come up with something to support it level on both sides of the machine. (And you can only feed forward with the material - it does not back up.) But it will be an interesting experiment. Can’t wait to see it! 
Yeah, what she said!
Get a couple of these. They’re perfect for feeding long materials through laser pass throughs. You can also create a table by putting 2 of these in front and 2 behind and laying a plank on them - just adjust the height to your feed slot.
Exactly what I got. (Although you do have to be very careful not to trip over the danged things when shifting your material. AMHIK.) 
The Redsail has a 9" tall pass-through so some stuff (like cabinet doors, signs, etc) are pretty thick & pretty heavy so rollers were critical.
But long 1/4" stuff in the GF will sag so putting another board on the rollers and making a table will keep it from drooping in between the rollers and the GF.
I might just build mini-tables, fore and aft. (I’m noodling with a clamp type arrangement in lieu of - and if I can make that work, it might be the most space efficient method. It only has to be level as it enters and exits the machine. And if I start running long material through, it’s going to have to block the doorway.)
But yeah, 1/4" material is floppy, and anything less is much worse. I tried some 1/8" material. Bwa-hahahahahaha. 
You could laser a simple jig that holds rolling pins on each side of the laser and attach it to a sturdy 2x4 frame… plenty of DIY rollers on pinterest for Woodshops and the like. 
If you do, face them with laminate, preferable the slightly nubbly kind. You can almost cedrtainly find cheap/free offcuts. And then everything just slides.