Wall-discharge toilets like the Yorkville need to be anchored into the floor (no flange bolts there) and they are heavy. So far I was able to drill through the tile and the 2" mud bed until the plywood underlayment appeared and then drive 5/16" lag bolts. Very sturdy.
Now we are thinking about installing something like a Yorkville downstairs where there is just slab. The really large 10mm Nylon wall anchors won't take more than a 1/4" screw though. Would that be enough to hold one of those monsters down even if a really heavy-set guy (no, not me ...) plops down on it?