Can you see if it has a 'Tuning Control' section in WattMan or not? My RX Vega 56 has it, but my RX 580 does not.
The 'Auto Overclock Memory' does nothing I can discern.
The 'Auto Undervolt GPU' choice seems to put the chip down to bouncing around in the range 0.96-1.11 V, 135 to 150 W for 1468 to 1486 MHz
versus 1.00 to 1.16 V, 158 to 173 W, and 1483 to 1493 MHz in WattMan's Turbo mode.
(All figures from GPU-Z, IIRC my physical BIOS selector is for the lower-power secondary BIOS. Does the Radeon VII have that?)
I've not tested 'Auto Overclock GPU' yet.
Desktop: E3-1270 v5, X11SAT-F, 32GB, RX Vega 56, 500GB Crucial P1, 2TB Ultrastar, Xonar DGX, XL2730Z + G2420HDB
HTPC: i5-2500K, DH67GD, 6GB, RX 580, 250GB MX500, 1.5TB Barracuda