I have been running wheel adaptors with spacers for years with zero problems.
Maybe if the wheels are cheap shit that don’t have a concentric hole pattern it would be a problem. :gotme:
With today’s technology there is really no excuse to make wheels with bolt circles that are not true.
The only way it may be an issue is if the wheels do not have “seats”(chamfer or ball seat).
My Evo had nuts that did not “center” themselves but, I think most cars do.
Good job in springing for the spare! I did the same thing years ago and had to use it this past spring when I found a massive pothole the hard way. If I didn’t buy that spare, I would of been screwed because the rims are no longer made.