As of
ver.1.04.090b8e5169:
"Sonic Forces.exe"+20B36B8, 4 bytes. This is the HUD width scale, set it to any value to change the width of the HUD.
Attachment:
File comment: 2560
Sonic Forces Screenshot 2017.11.23 - 12.43.25.22.png [ 4.27 MiB | Viewed 2183 times ]
"Sonic Forces.exe"+1DBDC5C, float. This is the aspect ratio, divide width by height to get the value for your resolution.
Attachment:
File comment: 2560/1080=2.37037037037037
Sonic Forces Screenshot 2017.11.23 - 12.44.18.98.png [ 4.42 MiB | Viewed 2180 times ]
NOTE: You don't need to change the HUD width scale at all. Just changing the aspect ratio then changing the resolution of the game itself will make the HUD width scale change.
This isn't the vert+ widescreen behavior, but it does allow for wider aspect ratios at least.