Halldor Helgason demonstrates this one brilliantly. It’s pretty much the same as the previous trick, but with two crucial differences.
1) This is backside, so approach with the rail behind you.
2) It’s a tailpress. So when you ollie onto the rail, instead of keeping your weight even over both feet (as you would for the 50-50) shift your hips back over the tail to press it into the rail.
3) Wind up your shoulders and pop that 360 round as you come off the end. Doesn’t releasing that tension feel good?