unified song format

I'm building an album project and have designed the basic instrumental structure for 2 songs, which will work for the rest of the project.

How do I ensure that the subsequent songs have the same instrumentation?

'Total replace' of Environment doesn't populate the Audio Instrument or plugin slots.

why not - indeed :-(
As I usually work on one-song projects, or album projects where the client is likely to chop and change orchestration, or straightforward kbd-bass-drums - the only time I use Templates is for Autoloads - one for default, and a few for testing various settings configurations.

So the solution wasn't ready-to-hand - one brain good two brains better!