The īśvāra-praṇidhāna of the
PYŚ, for example, often takes on a more sectarian flavor in
the later texts, such as śaṅkara-pūjanaṃ in
the Śivayogadīpikā.
Sankarapuujanam need be taken to be 'a sectarian flavour'. For,
Isvara denotes only Siva as we find in all the Upanishads and other
texts; Svetasvataropanishad repeats this word many times and it can
not be interpreted in other ways.
As Kalidasa says in the invocatory verse of his drama,
Vikramorvasiyam,
Isvara denotes only Siva from the early period. Kalidasa is of the
firm view that the entire Vedanta corpus
(vedānteṣu)
proclaims Siva to be the highest Reality (puruṣa) that
pervades all the universe.
Kalidasa and Patanjali definitely belong to very early period.
Thus by īśvāra-praṇidhāna it is fully
plausible and also possible, that Patanjali meant only
worship of Siva. And, worshipping a supreme God need not be
interpreted as ''sectarian''. One cannot ''worship'' a supreme
reality which is nirguna.