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 "conductive material". 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.