Optimisation & decals problem ! (translucency ?)

Hello everyone,

I’m now learning game optimization in more details, and i’ve seen in the “GPU Visualizer” this :

I presume that it have to be Decals who take a lot of performance and translucency ?
This is a screenshot of the decals master material, please tell me if someone need a zoom for more details on the BP.

I use decals to put some graffiti in the street… so my question is, do you think there is a better way than decals with translucency for better optimization ?
Or maybe still use translucency, but with some optimization in it ?

Tell me any other ideas please, also if you need more informations.

Thanks a lot !

Oh i’m sorry, but i forget that i have two kind of decals here and not using the same master decal material…

There is the first one :


And the second one :