Two protuding structures at the front, except the missile hardpoint and what seems to be a bridge, might be the cargo container. Or at leasr the structures containing it.
The flight deck appears to be in that forward structure; fighters appear to dock with the Gemini by entering the slightly indented side areas on the forward section or the lighted sections on the back of the forward section in the gap between the forward and rear sections, and launch from the same four areas. Interestingly, the drones seem to have a separate bay with a launch chute between the thrusters on the rear section rather than launching from the flight deck used by the fighters.
I personally suspect that the cargo container is probably hidden beneath the flight deck and thus not visible on the sprite, or if it is visible, then only parts of it are visible and they show as some of the 'lower' features of the forward section.
And also the presence of what looks like a rail running halfway down to the ship's spine makes me quite curious. Is it like a airplane catapult? Or part of the container seperation mechanism?
If you're talking about the apparently raised segment that runs along the bottom of the somewhat semicircular region on the forward section, I don't think it's part of the container separation mechanism; it looks too high on the ship to be part of that. I also don't think it's a catapult launching fighters; it could be a brace for such, but it again looks to me as though it's too high up on the ship compared to where the fighters are launched from to be a catapult. I suspect that it's more in the line of a major structural element connecting the flight deck to the spar connecting the forward and rear sections of the ship.
If you're talking about the black line running about a third or half of the way up the connecting section between the forward and rear sections, I don't think that has anything to do with the flight deck or the cargo container; I suspect that it's just a region of the hull which for some reason isn't at the same level as the sections on either side of it. Fighters don't appear to launch from that area, while drones appear to launch from further back and dock with the Gemini somewhere in the gap between the forward and rear sections, sort of at the points where the connecting section meets the rear section. It is in the right area for the drone bay, but I'd tend to suspect it to be more of a gap between docking tubes leading into the drone bay than (part of) a catapult for launching the drones.
Aside from that, do you think that the variant would fit in a role nicely? Like... a destroyer-sized combat carrier?
More like a (D) variant, but not uniformly negative.
I agree with HartLord that if this were implemented it'd be more of a not entirely negative (D) variant Gemini than anything else; Geminis are already reasonably competent destroyer-scale combat carriers, and I'm a bit doubtful that improved maneuverability would improve their combat performance enough to make it much better as a dedicated carrier unless the improvement in maneuverability were significant (also depends on whether we're including maximum linear speed in maneuverability, or if we're just talking about increased maximum rotational speed, rotational acceleration, and perhaps linear acceleration when we say 'improved maneuverability'; merely improving the accelerations and turn rate isn't likely to make me consider the containerless Gemini much better, if at all, as a combat vessel).