I'm actually trying to make the split planes, Vincent. The part I was missing was that drawing lines gives you tracks. This is my low voltage split plane. I have 1V5 DDR, 1V5 CPU, etc. I moved the layouts to group all power groups together and have multiple split planes now for power. Then I have a master 3V3 full plane.
From what I can see everything is working. Just not using the right Altium vernacular, must likely.