Viknesh
Śrī Mātre Namaḥ,
Among so many published Tantric texts in some Indian languages (many are out of print) only some authors are actual upasakas who have given the knowledge about deities, their mantras, yantras etc. from experience while many are academicians who translated texts from Sanskrit into other languages.
Getting information about the upasana of a Avadhuta like Gurugaru is impossible. Even if you get it how sure you are the information is accurate?
Guruji also said somewhere that a guru is needed to understand the hidden meaning in Tantras.