We want our main build to run as quickly as possible, so we have the "Clean all files before build" option unticked.
However, we occasionally find that bites us, when a "stale" files from a previous build allow a new build to succeed, until we eventually do a "Clean all files before build" and get a failed build.
We have worked around this by setting up a copy of that build configuration, which runs at lunchtime & with the "Clean all files before build" option ticked. This works fine, but adds clutter to our TeamCity project page.
It would be great if the "Scheduled" build trigger had an additional option to force the "Clean all files before build" setting, only when the build was triggered from that trigger.