Well it's obviously OK from a general "it's a free country" point of view. But from the point of maximizing the strength benefits from the progressions, then no, it's not OK. Coach Sommer has repeatedly emphasized that keeping the arms straight from the very beginning is crucial.
What happends if you keep your arms straight? How long can you hold that? 1 second? Less?
A few questions:
How tall/heavy are you?
How long have you been trying?
How often have you been working them?
Do the holds add up to 1 minute of cumulative work?