Thanks for your help Carl! A *.cmd file set to run under saved administrative credentials as a scheduled startup task works to delete the file on windows startup:
:: Delete Ignition .sessions file to avoid auto logon failure due to delay in removing previous session
:: Run as scheduled startup task set to run as a local admin with saved credentials
@echo off
del "C:\Program Files\Inductive Automation\Ignition\data\.sessions" /F
After that, a simple clientlauncher.exe shortcut (with desired command line parameters) works to start the local client without auto login failures due to the old local client’s session still be counted (I verified the ghost session was the old local client session by refreshing the gateway’s session details web page right when auto login failed: it showed the old local client along with up time that exceeded the amount of time since reboot–refreshing a minute later removed the old local client).
Deleting the .sessions file resolves the auto login failures due to past session counted in error until it’s timeout expires. This is great; eliminating the *.cmd file with delay speeds start-ups after reboot (from power outage, downtime, or whatever). The HMI is up at least a minute earlier than before.
Are there any bad side effects to deleting this file? Could the file be eliminated to avoid the need for this workaround?