You never really HAVE to put a Spacesaver on a front wheel. If you get a front wheel puncture/damage, remove that wheel and fit the Spacesaver. Go to a back wheel and remove a (good) one, and fit the punctured wheel. Go back to the Spacesaver (just fitted toi the front) remove it and fit the good (ex) back wheel. Return to the punctured rear wheel and fit the Spacesaver.
Tedious I know but means you don't ever have a Spacesaver on the front
IF, you have two jacks you can jack front and rear of the same side at the same time and just swop front to back so the Spacesaver goes on the back.. I DO NOT RECOMMEND THIS METHOD.
However the good old Citroen 2 CV jack lifted the whole side of the "Deuch" allowing both wheels to come off at the same time. Just shows you how advanced that car was, in it's own way
Whatever you do ,do it SAFELY a car coming off a jack can do an awful lot of damage, to you, others, and the car