If my spouse and I file for an extension to file as joint taxpayers, can we change our filing status to filing individually before the extended filing date?

I understand that taxpayers who file joint return may NOT amend their filing status to filing individually AFTER they have filed a return.  However, if they make a joint request to extend their filing date until October 15th, are they permitted to change their filing status before filing their return on or before October 15th?