I made this filter https://www.printables.com/model/1276996-recirculating-carbon-hepa-filter-for-sv08 and attach it to heat-set inserts in the top hat I made rather than to the mounting holes for the spool holder (as I've got the spool holder attached there). It's definitely filtering, but even with a 12V fan being run at 24V, it's not enough to make the air in the printer fully unsmelly, and not enough to stop the smelly air that leaks making the whole room smell of molten ABS.

There are higher-performance filters like the various Nevermore designs, but they're more of a pain to print and more complicated than they need to be, and don't fit anywhere in an SV08 without getting in the way of something and sacrificing print volume.