Inline Carbon Filter For Closed Loop Extractors?

I see one of the higher end Tamisium models has an inline filter you fill with carbon. the material passes through this filter prior to entering the recovery tank. If i could put something like this inline after a true stage 1 dewax it seems like it would skip the need for a carrier solvent/winterization and a rotovap to do these same steps. Is there someone that makes a filter like this that could be used on a system with a 6" base and 3" material columns?

also, this may seem dumb but why should you not just add the carbon to the bottom of the material column?
 
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