To my knowledge, Veṅkaṭanātha’s Seśvaramīmāṃsā has been commented upon only once in Sanskrit, namely in the 20th c. by Abhinavadeśika Vīrarāghavācārya.
At times, the Sūkṣmārthaṭīkā‘s author seems to disagree with Veṅkaṭanātha insofar as he stresses that a certain position by the Mīmāṃsā school is “not accepted by us” (i.e., by the Viśiṣṭādvaita Vedāntins). Many such cases pertain to the core teachings about language and the Veda being fix according to Mīmāṃsā and depending on God according to Viśiṣṭādvaita Vedānta. In the commentary on SM ad PMS 1.1.29, the Sūkṣmārthaṭīkā is quite explicit:

By contrast, we do not accept the inference said by Mīmāṃsakas, namely ”Each recitation of the Veda has been preceded by one’s teacher’s teaching one the recitation of the Veda, because it is a Vedic recitation, like the present ones”. We do not accept it, because there is an exception, since the probans is absent in the recitation performed by Brahmā of the [Vedic text] based on the Lord (who was Brahmā’s inner controller, so that Brahmā did not need to learn the Veda from a teacher) as well as in the present recitation of the Veda, when it is performed by an ascetic who has made it present (and therefore can see it without the need of a teacher).
And we also do not accept the syllogism because it contradicts the sacred texts speaking of creation and dissolution [of the entire world].

vedādhyayanaṃ sarvaṃ gurvadhyapanapūrvakam adhyayanatvād ity anumānaṃ tu mīmāṃsakoktaṃ necchāmaḥ. īśvaramūlacaturmukhakartṛkādhyayane sākṣātkāritapasvikārite ādyādhyayane ca sādhyābhāvāt vyabhicārāt (ad SM ad 1.1.29, 1971 edition p. 128).

It is easy to see how a Mīmāṃsaka could not have agreed less with Vīrarāghavācārya’s arguments. Mīmāṃsā authors in general believe in a beginningless time and think that the idea of creations and dissolutions is only an unwarranted assumption. Even more dangerous is the idea that an ascetic might see directly the Veda, since this could open the door to yogipratyakṣa and to autonomous religious experiences.

In all the above ways, the Sūkṣmārthaṭīkā‘s author also indirectly points out the gigantic effort Veṅkaṭanātha undertook, almost seven centuries before, when he tried to propose a synthesis of Pūrva Mīmāṃsā and Vedānta.