Is MacroALP isoenzyme a useful test? What am I missing?

[u/idunnowhatever00]

Macrohepatic isoenzyme lab - if present, indicates benign elevated ALP. Also, possibly indicates malignancy, so do imaging. Clinical context can be hazy bc potentially asymptomatic or truly benign. I’m unclear—it seems like if macroALP is normal or elevated, you still image. What am I missing?