Got it. Linguistically, "the object will be or was located" is fairly vague, and it seems to me that the adverb clauses serve to specify the exact times meant by "will be" and "was". Using the definite article in "the object", rather than a phrase like "such an object", has to refer back to something recent, like the two phrases "an object" which are definitely modified by those time restrictions.
And in your interpretation, the "before ..., or after ..." conditions modify only the main clause of that same sentence, i.e. "any pointer that ... may be used, but only in limited ways"? Then what are those limited ways it may be used, or the limitations on its use? Does any other clause in the Standard elaborate that case, if the following sentences and paragraphs don't?
To be very specific, an example:
#include <string>
#include <new>
union U {
int n;
std::string s;
U() {} // no member initialized
~U() {}
};
void f() {
U u;
std::string* p = new((void*) &u.s) std::string("hello");
p->~std::string();
// The lifetime of the object p pointed at has ended, but its storage has not been reused or released.
// At this point, how can p be used and how may it not be used?
*p; // ok?
}