Is it commendable to change the place of supererogatory prayer after the obligatory prayer so that more than one spot on Earth may bear witness for me?

It is recommended to separate the obligatory prayer (Fard) from the supererogatory prayer (Nafl) with speech or by moving to another place. The best separation is to move home, based on the Prophet's (ﷺ) saying: "The best prayer of a person is in his home, except for the obligatory prayer." The evidence for separation is what Muslim narrated from Mu'awiyah: "When you pray Jumu'ah, do not follow it with another prayer until you speak or leave, for the Messenger of Allah (ﷺ) commanded us to do so: not to join one prayer to another until we speak or leave." Al-Nawawi said: "This contains evidence for what our companions said, that it is recommended for one to move from the place of the obligatory prayer to another place for the supererogatory prayer. The best is to move home, otherwise, to another place in the mosque or elsewhere, so as to multiply the places of his prostration, and so that the form of the supererogatory prayer is distinct from the form of the obligatory prayer." The reason for separation is to distinguish the obligatory prayer from the supererogatory one and to multiply the places of prostration, which will bear witness for the worshipper on the Day of Judgment.