You'll find the setting under System Preferences > Accessibility > Mouse & Trackpad > Trackpad options... > Enable dragging > three finger drag
This works great for moving controls in software such as Reason without having to click and apply pressure. The upshot is it seems to remove the ability to use the three finger gestures for other things. Swiping between full-screen apps then becomes a four finger swipe. Anybody else here using this or knew about this trick? Any other hidden features in macOS that you use?
Something I found when I enabled the three finger drag via Accessibility, it that it seems to have also automatically enabled 'tap to click' under the regular Trackpad settings (System Preferences > Trackpad > Point & Click). I don't like that feature, but was able to turn it off and keep the three finger drag behavior. Not sure if anybody else might encounter this, but figured I'd give the heads up.