A nice addition for captains in the lobby would be the ability to request certain loadouts for their crew.
The way this would go about is, beforehand, the captain would build loadout sheets similarly to how you modify your equipment right now. However, they can also add to the tooltips of the different ammo types/engineering equipment so the crewmates can see the captain's logic.
i.e. Say I'm running a blenderfish. For the gunner, I'd have him bring Heavy, Charged, and Incendiary rounds. I'd have a tooltip over Heavy Clip describing exactly what it does and why it's needed "Heavy Clip will tighten the spread of the forward Carronade, making it ideal for medium to long ranges." Then I'd probably have one for both Charged and Incendiary reading "Charged is a direct boost in DPS, but, without the accuracy bonus of the Heavy Clip, it will make your shots extremely unreliable. Use at close ranges when we are just about literally in their faces. Also, Incendiary LIGHTS STUFF ON FIRE. That alone should give you reason to use it. I'd suggest alternating between Incendiary and Charged for the best effect."
Then, during the lobby, Captains can just right click their crew mates, hit a "Request Loadout" button, and then select whatever loadout sheet they want to send.
For the crewmembers, they'd get a notification of this, and, after looking it over, would get to decide whether to follow through with this or not.
Sure, you may ask "why add this whole system in the first place when messaging the crew works well enough?" It does, but it takes a while for me to type up instructions for everyone. If I could just quickly send my recommendations to the crew quickly and easily instead of taking five minutes to explain things to everyone, then it'd be a lot easier for me to make sure everyone knows what they're doing and how/why to use this or that.