<Style TargetType="{x:Type igDP:RecordListControl}">
            <Setter Property="Template">
              <Setter.Value>
                <ControlTemplate TargetType="{x:Type igDP:RecordListControl}">
                  <ScrollViewer CanContentScroll="True" Focusable="false" HorizontalScrollBarVisibility="Visible"
                      VerticalScrollBarVisibility="Visible" ScrollChanged="ScrollViewer_ScrollChanged">
                    <ItemsPresenter RenderTransform="{TemplateBinding ScrollableElementTransform}" />
                  </ScrollViewer>
                </ControlTemplate>
              </Setter.Value>
            </Setter>
          </Style>

I need the ScrollViewer_ScrollChanged so to align other Scrolls with it.

Why it doesn't work when CanContentScroll="False" is set for smoothe scrolling (it cuts off certaing amount of Records at the end)?

Why there is a ViewPort Height change when CanContentScroll = "True"? - this looks like the issue

Another option is to Scroll RecordListControl based on external scrolls, but it looks harder to implement.