I find that I always need to set the following compatibilty settings on reinstalling DisplayFusion:

Opera browser (any build/branch):
Application: C:\Program Files (x86)\Opera*\opera.exe
Disable middle-click window moving (this application only)

Reason: Opera, like other browsers, uses middle-click to quickly close tabs on the tab bar.
The wildcard path \Opera*\ makes sure it catches the various branches (\Opera\, \Opera beta\, \Opera developer\) and builds (version number in path).

Steam:
Application: C:\Program Files (x86)\Steam\Steam.exe
Normal & Maximized TitleBar Button Offset: 295 30

Reason: The Steam client draws a very non-standard window and the DisplayFusion TitleBar Buttons will by default be drawn overtop the Steam account name, wallet money, and/or messages button.
These compatibility settings move the buttons directly below the Min/Max/Close triad where the Steam window draws just empty space.. Unfortunately with detault buttons for Win10 (XP dark) they're invisible against the Steam window, but at least they show on mouse over.

Opera -- hey, what do you know, it's fixed even on the developer branch! Great. That removes the issue for me. I guess I just mis-clicked the tab when I installed Win10 and assumed it was still broken.

For Steam, DF buttons by default overlap my wallet and 'envelope' item, because I have an old Steam account where my username is an email address (more than 10 chars).
Anyway, just sharing these since others may be running into the same issue ☺