What can I do to improve my sprint time to sub 40?

[Skyfire]

Just got 44.954 seconds in 40L Sprint today, so I'm quite pleased (beat PB by 2.5 seconds). However, I want to get under sub-40 over the next couple of months. Here's the replay to analyze:

https://youtu.be/1O-PTnTdyp4

There are a few problems that I want tips on to fix:
1. I constantly hesitate by a small amount because I try to find optimal placements for my next few pieces. I also end up slowing down/pausing when my stack or piece placement gets awkward.

2. I end up confusing complementary pieces (J/L, S/Z) in my previews sometimes when I go fast (maybe too fast). It's not apparent in this replay, but it happens often. What happens is that I'm expecting an orange L piece when my actual piece ends up being a blue J piece and I get confused (note that I'm not directly looking at my previews; they are at the edge of my vision so I try going by color).

3. I go back to old habits of triple tapping instead of using two-step finesse correctly for some of my pieces.

What are some tips/practice methods that I can do to fix the problems stated? If there is anything else to note about my replay, then I would love to know. Thank you!

[Skyfire]

Bump

[XaeL]

You aren't using enough previews. This is obvious from the pausing.

Your finesse is ok but still needs some work. Ideally if you do stall it should ideally be during the start of a piece rather the end input of a piece.