Have they started putting stronger pickups in these yet?
I don't think so. While the first two SX 6ers I bought had stronger pickups (did not have the ceramic magnet on the bottom) the last one including the ash body I got from Chuck Norriss had the weaker ones. On that Ash one one of the pickups had the cover come loose (it's just stuck on with silicone bathtub caulk) and I noticed that the coil on the pickup didn't fill out the form on the pickup meaning it's considerably underwound. And that accounts for the low output.
However, if you do the Neo magnet mod it boosts the output (depending on if you use a 1/8" or 1/4" thick magnet on the bottom) and then this with the under-winding makes for brighter more defined pickup with very nice alembic-like clarity. They are still single coil, of course, but can sound very nice. The benefit of the neo boost is that it boosts output without boosting single coil hum levels.