I want to rotate resource labels the same way you proposed it for Resources / Schedule view.
Can I make customizations to a specific view only?
CSS modifications to the calendar can be formatted to only apply to a specific view. Adding one of the following selectors to the beginning of your CSS will specify which view to apply the CSS to:
Name of CSS selector -- Corresponding tab in the calendar
.fc-view-agendaDay -- Day view with times down the left side
.fc-view-basicDay -- Simple Day View
.fc-view-agendaWeek -- Week view with times down the left side
.fc-view-basicWeek -- Simple Week View
.fc-view-month -- month view
.fc-view-basicHorizon -- Gantt Chart
.fc-view-agendaResourceVert -- Resource tab with times down left side
.fc-view-agendaResourceHor -- Pivot Schedule (was "Grid" view)
.fc-view-basicResourceVertz -- Resource tab, list view
.fc-view-basicResourceHor -- Pivot List
You can see an example of CSS applied specifically to the Horizon view in the following section.