Drop

if (!m_animations.isEmpty()) {
    effects->addRepaintFull();
}

in favor of

effects->addRepaintFull();

!m_animations.isEmpty() is redundant because when postPaintScreen is
called, we know that at least one animation is active. If there is only
one animation and it is about to be removed in the while loop, we still
would like to repaint(to "clean" up after the animation). So, in either case,
we would like to schedule repainting.

Yet, scheduling full repaint is not the greatest thing, but that was before.