How do i tweak several parameters ( ie delay feedback and any other knob from dly unit) simultaneously?
by placing the effect-engine in the widget-zone.
you get 6 buttons to use at the same time 
Still no luck , tried through menus
but can’t put engine to those knobs. How should i do that?
you can configure a lot of areas with the setup button
as suggested use the setup button and assign the FX to the softkeys… SETUP-FX-OPTIONS …it will look like this…:
Ray
Screen-Shot-2018-02-04-at-11.03.57-AM.pdf (189 KB)
Screen-Shot-2018-02-04-at-11.04.34-AM.pdf (108 KB)