Ok, after getting some ideas here and online, this is similar to what I ended up with:
The idea is to wet the layers to better grab smoke particles. I ended up modifying it slightly:
That is simply a five foot dryer duct extension taped onto the side of the unit.
Learned something about RTV here. The blue RTV you see around the fan did not stick to the PP box! Yet, the aluminum tape I used to secure the duct to the side worked fine.
Performance wise, the duct made the unit a lot more versatile. I can move the suction to just about anywhere I need it without having to move the entire unit. The range appears to be up to about 6". I used the strongest fan I could find, a 120mm one rated at 78 cfm. If I wanted to spend more, I know there are some close to double that cfm.
I didn't have any incense to try, but the maker claims it filters it out well enough that he can't smell it. There's still one mod I think I will make and that is adding an activated carbon layer. There's another video online showing such a DIY filter attached to the fan using a non-functional fan. That would use the least carbon and make for easy changing.
The main drawback with the device is having to use the wet filters and it takes them a good twelve hours to dry and that's under a ceiling fan. Don't want to trade filtered air for mold!