The Tconstruct sledgehammer from Ex Nihlio Creatio won't mine compressed blocks at the speed that it should.

Since Ex Compressum adds the modifiers Smashing I & II, you will be able to make any tool an impromptu Ex Nihlio hammer. Adding those modifiers to the sledgehammer doesn't make the mining speed modifier apply to the compressed variants of Cobble, Gravel, Dirt, and Sand. Instead, you mine the compressed blocks with the wrong tool speed i.e. barehanded.

Is there any way to add those blocks to the minable table of the tool?

I want to avoid making an extra hammer(Cobble) and excavator(Gravel, Dirt, Sand) just for smashing compressed blocks.