What to do with the supplied spare tyre?

[seventyplus]

I have enjoyed reading the various posts about replacements tyres for the OEM RE 050A 215-45-R17,s and have looked at the various suggestions for my Liberty 3.0R.
I recently needed to replace my tyres and the Bridgestone web site recommended Adrenalin not the RE 050 A. I chose this option but I now have a completely unused RE 050A from the boot.
What I don't understand is how the spare tyre is to be used on a AWD car with directional and asymmetric tyres. Is the spare only useful to replace a punctured tyre? Or is there some acceptable rotation system other than left front to left back as is currently done and so uses only 4 tyres?
Otherwise changing from one tyre type to another becomes even more expensive as one then needs five tyres.
As a new member and, despite age, pretty dumb about modern car issues, I hope you will excuse what is probably a very naive post.

[Ric]

The RE050A is asymmetric, but not directional.
However, I've also read that once you've used a radial tyre, you shouldn't change the rotation direction, so a NEW spare can be put anywhere on the car, but a used one should only be used for emergencies, because it may now be on the opposite side to where it was previously.