It is Mustahabb (preferable) to break up the Sufoof (rows) and spread out
after the Fardh Salaat so that a person entering does not fall into doubt
regarding the Jamaat’s completion.
Concerning a Munfarid (person who performed his Fardh without Jamaat), it
will be better for him to shift to another place for his Sunnat and Nafl
Salaats as well. (Fataawa Darul Uloom vol.1 pg.243; Darul Ishaat)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai