The same core requirements apply again at extension: qualifying citizenship, a genuine match to a listed profession, current professional credentials, and prearranged, temporary work. An extension isn't a formality; it's a fresh look at whether the arrangement still qualifies as it did the first time.
Treat the extension as a new assessment
Don't assume approval last time guarantees approval again if circumstances have changed. Review whether the role, employer relationship, or credentials still match what was originally presented, and flag anything that's evolved, a promotion, added duties, a new manager, so it can be addressed in the extension rather than assumed to be covered by the earlier approval. Two points make that reassessment concrete rather than abstract.
The classification attaches to a particular employer and the position described, so the comparison to run is between the description that was relied upon last time and the work as it is actually performed now — which means someone has to read the earlier description rather than remembering it. And the underlying conditions all still apply on their own terms: the work must remain prearranged professional employment matching a listed profession, the applicant must still meet that profession's own requirements, and the arrangement must not have drifted into self-employment through a change in how the person is engaged or paid. Any one of those can have moved without anybody treating the change as significant.
Hypothetical example: a chemist's employer restructures its research group into a contracting arrangement partway through the authorized period, and the change in engaging entity, rather than anything about the science, is the item the extension review has to address first.