I hadn't seen your log yet this morning when I tried 1 minute for the first time myself. Whew! That was hard.
My SPM was a lot higher than your 33. When I do one of these short fast pieces I am turning it over as fast as I can, pulling hard with the tops of my feet to get the forward stroke moving. The average SPM on the monitor showed 41, but I was also counting strokes and got up to 45. Maybe I was hallucinating.
Hard? Cramming 41 (or 45) strokes into that minute is amazing! You almost DOUBLED your stroke count from normal.
And good tip about accelerating the recovery stroke by pulling the tops of your feet toward you....didn't see that one on the Concept II "Tips" video. :-)
I only do it when I am really trying to go fast, say under 1:50 pace. Not sure how important it is, but it does feel like it gets me moving faster.