Would like to use it on the game to get around the miniscule HUD issue, but seems the game is rigged to only use the wrappers provided by GOG.

EDIT:
SUCCESS!!!!

Managed to make the game accept dgVoodoo by deleting both the dxcfg and nglide config in the game's folder and setting the game to use the Glide rendering device (GlideDrv.GlideRenderDevice) in the WoT.ini file. This makes the game take its settings from the DirectX config tab of dgVoodoo. Works flawlessly for tackling the HUD issue (attached a screen from 1920x1440 resolution but the HUD size of 800x600).

Ran into one problem. Cinematics seemingly started refusing to play through dgVoodoo (only black screen with sound). Turns out, it's actually because of the ddraw.dll file. Do not use the one that comes with dgVoodoo!!!. Usually, to enable dgVoodoo for a game, you copy 4 files into the game's folder:
D3D8.dll
D3D9.dll
D3Dlmm.dll
DDraw.dll

However, Wheel of Time from GOG already contains a ddraw.dll file, which was specifically modified to play the game's cinematics properly. If you replace it with the one from dgVoodoo, it will lead to the cinematics not working. So just copy the 3 files.

Now I'm off to play through the game for the first time in glorious 1920x1440 with a normally readable HUD and text. Hope the above helps anyone trying to solve the same problem.