The Signal Editor block has the flexibility to interpolate each signal in each scenario individually. Therefore, when you open the block parameters for the Signal Editor, in the 'Parameters' section, there is the option to choose the 'Active signal'. Each active signal can have its own value for the interpolate property. Therefore, you will have to make each signal active in the dropdown and check the 'Interpolate' box if you want to interpolate for all signals. To streamline this process, you can create a script to set this property in the Signal Editor for all signals.
An alternative to this is to set the default properties for insertion to linear interpolation in the Signal Editor User Interface. However, this will only take effect for new signals and scenarios.
