Thanks for reply.
I am playing with Magica Voxel, importers work really great. However i decided to wait for Epics new material layered setup to be more mature, currently it crashes whole editor too much.
AS for destructible voxels, i think you posted some movie on discord that does exactly what i want.
However there was some problem of performance with multiple voxel actors. I made like 10 wall actors with checker pattern (empty and filled 3x3 squares on flat wall). And while running along such wall there was nasty popping of voxels, like voxel LOD. Its probably me doing (or not doing) something.
Anyway voxels wait for better material layers to be usable, because they are great.