Haven't stained, but many have - I believe Solar Lux is mentioned frequently. Need to avoid any oil-based stains - epoxy doesn't like it. AFA 'swirl marks' - no idea. Someone will happen along pretty quick, that knows.

FWIW - careful selection of your cedar can eliminate the need for stain. Can't post 'em - but I've built a couple of 'chocolate' boats, with varying degrees of darkness. One looks almost like dk walnut.