Hello!
I just bought Black Mesa (Steam Early Access) and noticed a weird problem when using ReShade with it: if I use any of the 0.18.x versions, the game stutters like Hell, but only when I move my mouse.
At this moment, my GPU usage climbs to 100% instantly (I can view it thanks to MSI Afterburner and my Logitech G19 LCD), which is I think the cause of the stuttering.
I tested several old versions of ReShade and it seems that only the 0.18.x versions causes this behaviour, the more recent ReShade version that works well with this game is the 0.17.1, but it has some issues with hotkeys.