I suggest you the Robowealth Blog, Finbacial Hacker and of course the Black Book 3rd edition.

Then there is the question about what you want to achieve.
Actually I did create a somewhat nice Currency strength strategy.

Just I moved on for now, cause I need sometzhing faster (higher trading frequency) the trades where hold on to pretty long.
But I plan on going back to it.

So of course, you can save the returned value of that function, and use it in your trading decisions.
Not only the weakest / strongest.

But, reading the code, it says all basis currencies / other, that means, e.g. I have also USD/MXN but e.g. no EUR/MXN so that would mess up the calculation.
The sample code works, also the returns are / depending on the chosen comparison indicator, threshold etc. not the greatest.

Did not die deeper into that.

I would also encourage you to check the demo script and article of Petra on the financial hacker about CCY.