I was told on the Arduino Forum that this was the solution,

“You can flash two sketches included in one sketch. All you need is a configuration bit that shall has to be read during reset to start either sketch1 or sketch2. p.s. In this case the use of function pointers is recommended.”

But one as a novice I don't know how to do that and searching on Google haven't found a solution that talks me through its step by step and two I was hoping having thoughts over it wouldn't I be able to replicate / duplicate by copying the sketch from the first PC in Simhub to the laptop Simhub?

any help much appreciated and here is the project video I was able to follow on me first PC successfully if it helps you visualize what I'm trying to do.