https://bugs.winehq.org/show_bug.cgi?id=25912
--- Comment #60 from Tex Hipp texas.hippocampus@gmail.com --- Okay, now I really must be hallucinating!
xsitian's suggestion reminded me to poke around the settings within SketchUp itself. In Window > System Preferences > Drawing > Click Style, I see three options in SketchUp 8; the default selection in my install was "Auto detect". I changed it to "Click-drag-release" and the one-mouse-event-behind appears to have disappeared! I also changed it to "Click-move-click" and mouse selection still works fine.
But here's the thing that I can't quite wrap my head around: changing it back to "Auto detect" does *not* restore the one-mouse-event-behind issue. My mental model of how the software works under the hood does not align with what actually is going on. It's as if there's some kind of hysteresis. Is that even possible in software? I also have no idea why a setting for controlling the behavior of line mode would affect select mode, but it seems to be the case here.
I've tried this on several of my .skp files and the mouse clicking seems to perform properly in all of them, even after closing the application itself. I've also changed Vblank mode back "on" in nvidia-settings and moved the PowerMizer back to Auto and SketchUp 8 continues to select correctly.
This is scarcely believable to me, so I wouldn't blame others for thinking I inadvertently changed some other configuration that is actually fixing the problem, but I really did my best to be systematic and change only one thing at a time.