In most recent Pro version, '2018.1.3169', using the default Builder settings at https://builder.daypilot.org/calendar and angular implementation,
'<daypilot-calendar id="day" daypilot-config="dayConfig" daypilot-events="events"></daypilot-calendar>'
The allowEventOverlap property does not disallow event overlap. This was working in DEMO version, prior to installing the PRO version.