Use middle mouse button (scroll wheel) as Force Touch?
I managed to work it out: if you use BTT to map clicking the scroll wheel to the shortcut  ⌘  +  ctrl  +  D , it will show the dictionary lookup box for words, but also allows you to preview files in Finder (like pressing space) or Force Clicking a web link. I had this already configured in USB Overdrive, which explains why it worked before.

Hope this helps someone :)