Because I am more than capable. I just like to ask a lot of questions and tend to probably over worry about things as I am being a total paranoid perfectionist on this job.
Been using a lot of epoxy lately on my latest artistic glass mosaics, lots of tiny pieces or just a few mm in parts, different heights of glass, crazy paving pattern, sharp edges... and was a little apprehensive how well I could handle the epoxy that was a doddle when practising with 'normal' uncut glass mosaics - and it's been fine, and I reckon you'll find using plenty of hot water and the white scouring pad you will find that it'll be fine, too. The rough surface really wouldn't worry me now, actually I imagine it would be easier than having sharp points catching the sponge, rag, whatever.
Getting epoxy grout haze (bloom) off is no harder than getting normal cementitious grout off. Just follow the instructions and make sure you have an Epoxy grout sponge to hand and a spray water bottle. It's a breeze.