You mean the zoom feature? You can set it to double click in Gesture options, I’m finding that more useful than the default. But this can lead to accidental zooming, of course, if you tap the screen repeatedly to shoot something.
But damn, you’re right about the sliders. I could’ve sworn there’s a keyboard shortcut for that, but Syndicate seems to be 100% mouse-driven. Guess it was pretty innovative and fancy back then not to press any keyboard keys… ?
Apart from that, your workaround sounds very good. That’s what the Target widget was designed for. And I second the request for Target widget integration into Looper widget. ?