Since the plugin uses its own canvas blend modes or effects used on Construct 2 layers won't take effect.
Sadly there isn't really a workaround for this other than making the plugin render to a texture instead that then would be it's own C2 plugin to be placed on a layer - I believe this is what the Q3D plugin did for example.
I have mentioned in other places that this was also my initial plan which I failed at and fell back on the straightforward additional canvas solution. I also said I may be revisiting this at a later date.
Be aware though such a change wouldn't be trivial and require reworking any projects you may already have too. It's not a can of worms I plan to open any time before 1.0 to be honest.
I'm sorry if this makes things difficult for your project.