If there is dispute over just 1 piece of property left to 4 heirs in a will - which has already been put into probate - is it possible to "close out" the rest of the succession and separate the 1 piece of property to be decided upon either later or individually of the remaining assets? And by property, I mean real estate, specifically commercial.
Thank you!

Yes (and no).
Yes the estate may be settled without separation of the property in question, as long as all parties agree to joint ownership. Later, the ownership can change.
No, if any one of the heirs chooses to file a "partition". The other heirs MUST either "buy out" that heir or a sale will be forced by law.