Long story short: (ENB) Vsync is causing the increased load times.
Observation: When ENB Vsync is activated, the initial loading time (from the main menu) takes upwards of 75 sec, versus 10 to 15s normally. The load time for transitioning areas in the game isn't as drastically impacted as it only goes from ~7 to ~17s on average.
Same happens if Vsync is forced through the NVidia driver, and de-activated in ENB.
The details: There's some weird behaviour as well. When ENB is completely off, the game Vsync works as intended. When ENB is in the game folder, with ENB Vsync off, the game Vsync does not work properly. There's either strange screen tearing -- strange as in the tear is at a fixed place on the screen, or stuttering (with variable frame rate). ENB FPS limit doesn't help. I have tried almost all combinations of ENB and game settings, and in the end, only 2 settings are completely smooth:
- (1) ENB Vsync ON
(2) Game Vsync ON, with ENB uninstalled
For info, the rig: Core i7 4790K, GTX970, 16GB ram.