What really doesn't work here is 5 solid minutes between Spock engaging the truster pack and then picking up the action with him again. It also makes Kirk look dumb. He's not chasing after Spock...he's just puttering around with Rand. Why?
I get this is just for fun, but you probably need to rethink the order of the events here because it just has no rhythm or pace.
Calling this the "missing memory wall scenes" isn't what you're doing. This is wholly new stuff you've used building from some scrapped footage, not the "missing" scenes as scripted.
Lol yes I didn't mean to claim that I recreated the entire scene as scripted! That would have been a feat! Apologies if you were disappointed.
You are not the first person to note the big gap. I had to consider the various possible interpretations and what was possible with the existing dialogue and the pre-existing script elements from In Thy Image and the TMP comic adaptation.
I also took inspiration from Dallas, Cain, and Lambert's exploration in Alien.
My decision-making went thusly:
1. Ilia's dialogue talks about detecting two carbon units but clearly there is so much footage of Spock on his own, there is no way I can shoehorn Kirk in there. Spock's journey works on its own and if I want to make use of footage of Nimoy in a different spacesuit, V'Ger needs to detect two other characters.
2. Equally, if, at the other end, Kirk is also alone then the scenes are REALLY boring. He needs someone to interact with.
3. I can only use characters who are not seen elsewhere later on so Rand seemed like a decent choice. I was influenced by the fact that it would be easier to colour correct the suit from science orange to engineering red and the fact that I had already trained Deepfake of Grace to give her an extra scene earlier in the edit.
4. Spock requires less oxygen than the humans and he has blasted off at high speed. Efforts to follow him need to be more cautious. No point firing at high speed in the wrong direction, especially if he's already dead. So exploring more cautiously and setting up some kind of emergency transport relay inside seemed like something sensible for the characters to try. This is something in Rand's skill set so I cribbed Simon Pegg's dialogue from Star Trek Beyond to produce some genuine Trek technobabble.
5. One criticism of the movie is a lack of warmth so I tried to inject a bit of camaraderie. Scotty's line reinforces his comfortable relationship with Kirk. Rand is babbling (inspired by Ensign Tilly and Lambert) trying to use humour to disguise the fact that she is terrified.
6. I think existing preconceptions about Spock's jet pack might be colouring people's interpretation as well. Since the DE does not establish Spock's jet pack as a one off burst (a really questionable piece of equipment) he does not need to keep blasting continuously until his fuel runs out but more likely in shorter bursts just to ensure enough speed to get through each aperture. So we are not viewing a continuation of him blasting inside V'Ger from 5 minutes earlier, we rejoin after he has passed through the Memory Wall and has blasted through a second aperture leading to the imaging chamber.
7. So, when he says he has penetrated the next chamber this is the chamber AFTER the Memory wall and we are rejoining him after his off camera memory wall commentary. I could see no reason why the same chamber should look so different and he needs to drift back through an aperture. Hence Kirk and Rand track him to the entrance to the imaging chamber and I tried to imply that Kirk was passing out of the Memory Wall area (being the blue glow in the background). Without full on CGI it is harder to establish their journey more definitively.
8. In some respects Kirk is acting dumb. McCoy, Scotty, and Rand tried to warn him. He pretty much confesses to Rand that he's doing it for his friend just before Spock returns. I was trying to evoke a Marshall Dillon and Kitty moment as an homage to the way the development of their relationship was pitched in TOS.
9. V'ger detects Rand's tricorder rather than Spock drifting largely on momentum making visual observations. Hence V'ger only detects two life forms and it's another example of Kirk pushing for a result that has bad consequences.
10. Rand's exclamation, 'somebody's out there', is a placeholder for the attack on Kirk should rough footage ever become available.
11. This version of Kirk is puttering around with Rand but he's still doing more than DE Kirk who just sits outside the ship passively waiting while Spock travels all the way in AND all the way back at a much slower speed. At least this Kirk meets him half way. :-)
Obviously, your mileage may vary but I did think quite carefully about what I was trying to achieve!