Re-entering Schengen Area before expiration of my Swedish visa

It is in practice unclear whether one needs to leave and re-enter the Schengen area in order to continue traveling in the area as a tourist after the expiry of a national long-stay visa or residence permit.

Reading the actual Schengen regulations, I cannot find anything that implies such a requirement. However, several people have independently related on this site that they were told by border/immigration officials they would need to do to that. So it would appear that, at the least, there's a risk that if you don't make a visa run, you may run into trouble when you leave the Area because you run into a border guard who thinks you need to do it. Perhaps the trouble would be cleared up when their superior gets involved, perhaps not.

In any case, the only halfway reasonable purpose of requiring a visa run would be to get an entry stamp in your passport that marks the beginning of your stay not under the residence permit. Thus, as long as you enter the Schengen area at another country than Sweden and do not actually go to Sweden, I think even confused border guards ought to allow starting the 90/180 day count at that day, even if your Swedish residence permit was still valid at that time.

Of course, you should also be sure to follow the actual 90/180 day rule, which says that every day where you have been in a Schengen country other than Sweden counts, no matter whether you went there from Sweden or indirectly.