Interestingly enough, when I actively monitored interactions, there are a lot fewer that influence Victor (and that is a positive for me).
Keep in mind this is an experienced captain who is the former engineer/union leader with most choices leaning pragmatic and calm, who is also of the save everyone ideal.
Long and major spoilers, obviously.
Summary
I did aim for the polite, positive interactions, even though most don’t directly effect Victor’s relationship. You will lose small amounts for helping the stranded ship and the irradiated Nova folk, but the are negligible.
Big choices:
With leadership as #1 or 2, when Oscar and Victor conflict over stopping to meet the Nova, calm them both down. Big Victor boost.
When TPES is coming on ship after the Thorn Chaser, Victor will ask you to keep his business private. Choosing to tell him he should try being nice when he doesn’t need something is a big boost.
On Mars, take him out to lunch at the small, out of the way restaurant, but explain it is because you won’t be looked for there. When he slips and talks about family, let it slide and chat about building a strong work relationship.
Celebrate the winter holidays and invite Victor. He won’t come, but he’s happy to be invited.
I failed on finding the stowaway before Victor, got between them in the fight, and gave Brogan safe haven. Victor summoned the captain for a drink… everything was null on effecting the relationship, until I chose the ‘don’t want to see you unhappy, you’re like crew’. After this point, Victor’s relationship was at 75%. He starts getting a bit touchy feely at this point i friendly ways.
Helping him with the cargo in the storm with no leverage took it to 80.
The next important scene is him inviting for drink and suggestion to join DRT. I chose being surprised DRT would want me and followed by asking if Victor was in danger. 84%.
My captain passed the TPES inspection and warned Brogan off Dylan, which led to the confrontation. I avoided any interactions against Victor until the option to say they have a positive working relationship, no need for blackmail. 85%.
In keeping the cargo from Solib using a bluffed ambush, there’s another boost. 88%.
Next interaction boost was after Becca comes onboard. I took Victor away privately to talk and offered to help with other merchants. 89%.
Lost 8% by going to save the merchant ship at the end, so I ended with 81%, became governor, and gave him assistant job. Voila Silver Fox scene.