1-2-4 means Index, middle and pinky.
So instead of trying to cover 4 frets with a finger span, which is what 1FPF would do, you cover 3 frets, or root (index) and octave (pinky). 1FPF is basically a guitar technique. On a bass it can work higher up the neck, where the frets are closer together, but lower down the larger spaces between frets can require stretching to reach some notes. If you have shovel hands you can cover more area but most of us don't and need a technique that makes playing easier, less tiring and the lines flow more easily. 1-2-4 does that.
Also, make sure your thumb (and whole hand) easily moves up and down the neck. If you anchor your thumb you will have to stretch to reach some notes, but if your thumb follows your fingers your whole hand will be moving and it will make your playing less stressful.
+1 for the turmeric.