I have a six-string lap steel that so far I have kept in C6 (CEGACE). I like it because I can play major or minor on it, but the tuning is seemingly built for hawaiian and classic country work, and that's not really where my interests are.
But, it seems like going to an Open D or Open G Vastapol or Spanish tuning would be a step backwards, toward tunings with all roots, thirds and fifths.
One rock player I know of with steel guitar interests is David Gilmour, but even if I knew his tuning, It wouldn't so much matter, because what I've seen is single-note stuff, so it almost wouldn't matter if he didn't have the other strings, so his preferred tuning isn't useful.
I get that the lap steel is not the most forward-looking instrument out there, but what are some tunings that would work in a more progressive or modern rock style?