The T3 layout panel has a button that has the label "Reset Positions". This button can be used to reset any changes to the module names changed in the layout panel since the template settings were last saved. This button does not reset changes to the module widths.
The "Reset All" button is used to reset any changes to the module widths since the last saved state for the template positions.
On the responsive layout panel there is an additional button with the label "reset layout for current device". This button is used to reset any changes to the widths assigned to each position for that current device. The widths are reset to the last saved state for these parameters.