yeah, i was thinking about that too. but, unless there is a better way to solve it, the puzzle you have to jump off the ladder and land on top of the spiny things head in order to get the key always killed me. i did a practise playthough in preperation for the speed run but i just couldn't manage to get that jump timed right. was always like 20 minutes just on that one puzzle for me.
I think even with such amount of wasted time, you can still make it. The only thing you have to bear in mind when doing the speedrun is that the game is kinda cheating on you: it asks you to do it under 45 minutes, but 1. will ALWAYS eat 5 minutes of the overall time, no matter how you do it.
If the time has gone over 40:00 minutes and you haven't entered 1. yet, it's game over.