The buttons on most MIDI and X-Keys controllers can be programmed vis the Shortcut feature to activate most functions in Instant Replay.
For more information see Shortcuts User Guide
Jog and shuttle wheels can also be used on supported devices such as the Behringer CMD PL-1 or the X-Keys XK-12 Jog and Shuttle.
Pay special attention to the Jog wheel configuration options when setting up a MIDI Shortcut. See Advanced MIDI Shortcuts
The ShuttlePro has 14 configurable buttons in addition to the Jog and Shuttle wheels.
To assign these buttons to shortcuts use the "ReplayA" to "ReplayO" Key options when creating a Shortcut in vMix.
See Shortcut Reference for a list of Instant Replay related functions that can be assigned.
A number of keyboard shortcuts can be configured using the existing Shortcuts feature in vMix.
For a full list of what is available see Shortcut Reference.
The mouse scroll wheel can be used at any time in the following ways:
With Shift key pressed: Slow down or speed up playback
With Ctrl key pressed: Move backwards or forwards one frame at a time.
With Alt key pressed: Move backwards or forwards one second at a time.