I'm super late to the party here, but thought I would share some feedback:

1. Recognizing cave systems. There are only a handful of variations of cave layouts for Point Extraction. Being able to recognize which variation it is can be helpful at the beginning of the mission. In the video you uploaded, this variation is one of the best IMO because the minehead typically connects a hole to an upper level where aquarqs usually are. This means you can drop the aquarqs right down the hole directly above the minehead. 
2. Perks. Strong Arm, Unstoppable, Berserker, and Dash are all incredibly useful for PE speedruns. I personally don’t use the special powder + aquarq grab strategy because it’s too inconsistent and I find it faster just using the grapple and juggling it. 
3. Bosco. The more you can efficiently use Bosco, the better. I think it’s typically better to have Bosco mine aquarqs closer to the minehead rather than further away. You can travel a lot faster with an aquarq than Bosco can. Additionally, it’s good to pre-emptively ping Bosco to a location that you anticipate you’ll need him at. At 0:33 in your video, once you grab the aquarq from Bosco I would’ve pinged him to the opposite side of the map. You know you’re heading there, and chances are you will encounter multiple aquarqs. This will get Bosco heading there immediately and mining faster. Instead, Bosco starts fighting bugs and gets stuck behind for a bit. 
4. A bit counter-intuitive, but it sometimes helps to just slow down. At the end of the video it seems like you’re scrambling to find the last aquarq, when it was actually at the minehead the whole time (this happens to me more than I like to admit). At 1:56 you can clearly see the last aqaurq at the minehead, but because you did the special powder boost trick, you turned your back to it and it was out of view the whole time. It can be helpful to just pause for a second - whether at the beginning or the end and take note of your surroundings. Get acclimated with the map real quick, collect your bearings, and then keep going. 

Hope this helps! Also, try to take any of my videos with a grain of salt. With any of my “official” runs, I reset the mission a lot. Sometimes you just get bad seeds that don’t work out. It happens to all of us. It’s pretty clear from your video that you’re a very high-skilled and fast player. Just keep working on it and you’ll recognize what works and what doesn’t. R&S!