Which Shaivite sect believes God is the operator of the Universe but not the source?

Question

As I discuss in this question, by far the most popular school of Hindu philosophy is the Vedanta school, which bases its tenets on the doctrines laid out in the Brahma Sutras, a work by the sage Vyasa that summarizes and systematizes the philosophical teachings of the Upanishads. You can read the Brahma Sutras here.

In any case, in Adhyaya 2 Pada 2 of the Brahma Sutras, Vyasa refutes various rival schools to Vedanta. In particular, he says this:

Topic-7: God Is Not a Mere Superintendent

37. For the Lord there can be no creatorship, for that leads to incongruity.

38. And (the incongruity arises) because of the impossibility of a relationship.

39. And (the position is untenable) because of the impossibility of (Nature) coming under (His) direction. (Or) And (God cannot be proved), since no physical support (adhisthana) is possible for Him.

40. Should it be argued that God will direct Nature like (a man directing) the organs, then it cannot be so, for that will result in God’s having experiences (of happiness, sorrow etc.). (Or) If a body, equipped with sense-organs, be assumed for God, (we say that) this is not possible; because of (consequent) experiences etc.

41. God will be subject to finitude or loss of omniscience.

Now most commentaries on the Brahma Sutras, including Adi Shankaracharya's Brahma Sutra Bhashya here and Ramanujacharya's Sri Bhashya here, interpret these Sutras as (in part) a refutation of the views expressed in the Shaiva Agamas, aka the Shaiva Tantras. But I found one commentary, the Srikantha Bhashya which you can read here, which has a very different perspective on things.

The Srikantha Bhashya was composed by Srikantha Sivacharya, a member of the Shaiva Siddhanta sect. Shaiva Siddhanta is a Shaivite sect based on the Shaiva Agamas and the poetry of the 63 Nayatanars, just as Sri Vaishnavism is based on the Pancharatra Agamas and the poetry of the 12 Alwars. So naturally you'd expect Srikantha to object to the notion that the Brahma Sutras are trying to refute Shaiva Siddhanta. Srikantha offers two potential alternative explanations for who Vyasa is criticizing:

1. In this excerpt from the Srikantha Bhashya, Srikantha says this:

   The Tantrikas, the so-called orthodox, those who profess to follow the Parameshwara Agamas, without knowing the real import of their teaching, hold that Pati, the Parameshwara, is the mere efficient cause, though, according to Shruti, he is both the material and the efficient cause of the universe.

2. In this later excerpt from the Srikantha Bhashya, Srikantha says this:

   Wherefore we maintain that this adhikarana refers to the Yoga-Smriti of Hiranyagarbha which speaks of Ishwara as the mere efficient cause. Therefore the adhikarana is properly intended to overthrow the Hiranyagarbhagama.

My question is about the two belief systems that Srikantha discusses. First of all, who are those "so-called orthodox" followers of Shaiva Agamas who believe that Ishwara is not the material cause of the Universe? Is this a reference to the Lakukisha's sect of Pashupata Shaivism, or Abhinava Gupta's sect of Kashmir Shaivism, or some rival sub-sect of Shaiva Siddhanta?

Second of all, is it true that the Yoga school, which was founded by Brahma or Hiranyagarbha as described in the Mahabharata, believes that Ishwara is the efficient cause of the Universe? It certainly believes that he's not the material cause, since it posits Pradhana/Prakriti as the material cause? But I'm not aware of any statement in the Yoga Sutras that says Ishwara is the efficient cause. I've just seen statements like the notion that he's the first teacher of Yoga, the notion of worshipping Ishwara, and the notion that he dwells within everyone.

For those who aren't acquainted with this philosophical terminology, the material cause of something refers to what it's made of, and the efficient cause of something is what causes it to happen. So "Brahman is the material cause of the Universe" means that everything is made of Brahman, and "Brahman is the efficient cause of the Universe" means that everything that happens is directed by Brahman.

Answer 1

According Siddha Tirumular, a saint who has written Tirumantram, important text of Shiva Siddhanta, Maya is material cause, the Lord is efficient cause and His cit/sakti is the instrumental cause.

Answer 2

It depends. There are 10 Shiva Agamas which support the above view, of Shiva only being the efficient cause. The 18 Rudrabheda Agamas are non dualistic cum dualistic. The Veerashaiva sect again follows a Philosophy similar to the Vedantic Vishistadvaita. The Kashmiri Shaiva school bases themselves on the 64 Bhairava Agamas which are Non dualistic, believing Shiva to the cause of literally everything. Also, if you notice, whenever an Agama is being revealed to someone Lord Shiva loves dearly with his heart, such as Maa Parvati, Lord Skanda or Lord Vishnu, the Agamas are generally non dualistic. Consider a few verses from the Sarvajnanottara Agama revealed to Lord Skanda by Lord Shiva

"This Lord Shiva who shines forth within the heart of all beings, who is self luminous, who represents himself as all the souls, worlds, worldly objects, who creates and directs all the tattvas, who is of the nature of all tattvas evolved by him from maya, who is inconceivable, who exists in the highest transcendental plane which is beyond the range of all other planes occupied by the and trancends all tattvas from Shiva tattva to prithvi tattva is verily beyond the reach of speech, mind and name"

Sarvajnanottara Agama Vidya Pada 2.4-5

Similar things have been said in the Devikalottara Agama. In fact, the Ajita Agama, one of the foremost of the Agamas among the list of 28 Agamas of South Indian Shaivism (10 Shivabheda and 18 Rudrabheda), has the following verses regarding this.

"The Lord(Shiva) is all that. There is nothing different from Him. He is the material cause,the mahat and the ahamkara, the tanmatras...... "

Ajita Agama 2.13-17

Also, notice, this Agama was again revealed to Lord Shiva's beloved Lord Vishnu. Indeed Vishnu is regarded as the foremost devotee of Lord Shiva in Shaivism.

The abover verse itself proves Lord Shiva is the material cause. The Shaiva Siddhanta of dualism primarily started from the Meykandar Shaastras. It is also true that Agamas like Paushkara, Mirgendra and Matanga do not accept Shiva as material cause. So the philosophy of the Shaiva Agamas is not easy. No one can just put one point label on it with superficial understanding