The d3d8/d3d9 situation on this front should be improved since f74b2cd . Otherwise, I don't think forcing anything not configurable in game is a good idea. Some of them have physics calculations tied to the frame-rate (which is generally expected to be 60 fps for older games).

Some of them have physics calculations tied to the frame-rate

For such games the framerate cap can be configured separately (many are already pre-configured inside DXVK), so that's barely an argument.

fwiw you can somewhat achieve this behavior with the below for d3d8/d3d9

d3d9.maxFrameRate = -1
d3d9.presentInterval = 1

Or the below for d3d10/d3d11

dxgi.maxFrameRate = -1
dxgi.syncInterval = 1

Though note this will always enable vsync for the game, not only when it is enabled ingame.

Edit:
Removing the second line makes the game control vsync behavior.
Note that if you are using dxvk in a environment where it can actively change the refresh rate of your monitor, e.g. X11 and regular Wine without fshack or on Windows, then the above won't be so useful for using your monitors max refresh rate. (i think)