By LogViewer, do you mean the Cloud Console web UI for Stackdriver Logging? If so, 1-2 minutes does sound a little longer than "usual" but not unheard of. Note however, that Stackdriver Logging does not define any
SLAs for latency expectations apart from downtime (which is not the case here).
Nevertheless, what you describe, if you believe it to be an issue with the platform, would be better reported on the
Issue Tracker as the App Engine Google Group is better suited for open discussion type conversations about architecture, best practices and the like. If you choose to file an issue there, please refer to this Groups thread in the issue and post a link to the issue here so that others in the community can follow along.