Will a 3D printed ESD dissipative housing prevent spark travelling through air hole to PCB?
I did some testing with a few materials and an ESD gun, shown here is for conductive foam. (I also did conductive plastic, not shown)

The spark would find the nearest &quot;conductive material&quot;. An interesting result was if a conductive aluminum plate was placed next conductive plastic, the spark actually preferred the plastic (the were almost identical heights.)
At the end of the day how conductive a material is doesn't matter much to a kV voltage, because once you start a plasma and breakdown occurs everything get's more conductive.
The conductive ABS-ESD7 has a volume resistivity of at least 10^4 Ω (highest being 10^9 Ω)
I have an ESD bench that has 10^9 Ω and sparks dissipate into that just fine, so at the end of the day I think you'll be fine. Any ESD events should dissipate in the plastic (as long as it is connected to a ground to return the transient voltage to the source).
Oh, and remember that air is Giga to terra ohms so to a kV source anything looks conductive to a source like that.