Quote - the scene may render better with GC checked.  then you can optimise various samples and shading rate.

I'd rather fix the problem at the source than use a bandaid. 

So far by turning off visible in raytracing for bikini top & necklace has solved the issue but I'd rather not resort to that.

Quote - Increase the Irradiance Cache and experiment with your shading rate.

Well the IC is max, so I'll try lowering the shading rate.