Nityananda Mahaprabhu regaularly worshipped a Sri-Yantra along with a Vaneswar Shiva Linga and an Ananta Shalagrama. These are still worshipped by His heirs at Khardaha, West Bengal.
According to some Gaudiya Vaishnavas, Krishna is 'Svayam Bhagavan' and one who worships Him should not worship any other deity.
Why then the closet companion of Lord Chaitanya,who is also worshipped along with Sri Chaitanya by the Gaudiya Vaishnavas worship Sri-Yantra and Vaneshvar Shiva regularly?
It seems that Nityananda Mahaprabhu did not obey or was above all the restrictions obeyed by the Vaishnavas regarding food and company by the way.