Just like Vaishnavas follow Pancharatra Agamas and Shaivites follow Shaiva Agamas, Shakta follow Shakta Agamas, aka Shakta Tantras. (I discuss an exception which proves the rule here.) One such Shakta Agama is the Todala Tantra. In Patala 5 of the Todala Tantra, Shiva tells Parvati about methods of worshiping Shiva. But in the course of doing so he makes one interesting prohibition:
Devi, one should never meditate on the deva with poison in his throat in the Kali yuga. If you want to perish, if you desire madness, you gain it by worshiping Nilakantha. If someone does the puja or actions of Nilakantha, it is like slaying me. Maheshani, if a fool should commit the sin of performing this prohibited action, he is a very wicked person. His son, wife and wealth are destroyed, no doubt, if he should do puja of the deva with poison in his throat. In this world, he becomes poverty-stricken and after death is reborn as a pig. If he should do purascarana of Nilakantha's mantra, he must certainly die within a fortnight.
My question is, why does the Todala Tantra prohibit the worship of Nilakantha during the Kali Yuga? For those who don't know, Nilakantha is a famous name of Shiva, referring to the fact that Shiva's throat turned blue when he drank the Kalahuta poison. So it's strange that he'd say "If someone does the puja or actions of Nilakantha, it is like slaying me." when he is Nilakantha.
I don't think this is a case of a Shakta text discouraging worship of a rival god, because this entire chapter of the Todala Tantra is devoted to worshiping Siva. Could this be related to Bhrigu's curse on Shiva that he can only be worshiped in Linga form, which I discuss in my answer here? That happened shortly before the story of Venkateshwara, which would align with the Kali Yuga timing mentioned in the quote.