If Rios was making his living running cargo, where was he putting the cargo? It's gotten me thinking that he was operating more outside accepted commercial cargo laws. Has there been more details released regarding Rios' history with La Sirena? Or details regarding the history of the ship itself?
Since Freecloud Control identifies Rios' ship by type as a "freighter" or "speed freighter", apparently without addressing user modifications, we really have to ask where the average operator of this ship type puts the freight.
A large portion of internal volume is taken by the already seen spaces, and the two-level center area is a perfectly fine cargo hold for the types of Federation cargo crates and containers so far seen, as well as for general goods. This area is served by the transporter pad and by four doors, one on each side on each level. This might well suffice for the "freighter" needs; we could then assume Rios added the cabins that flank the upper level (and apparently feature extensive holotechnology, so that the starboard cabin is a French vineyard and the two portside cabins overlap spatially), thus slightly reducing the available cargo space.
If the lower stern doors are supposed to be involved in cargo loading, too, we then have to further assume that the sickbay is a late Rios addition, too, as it now blocks access from astern. The stern doors might be for accessing Engineering or Fuel Tanks or whatever, though. But if they are cargo doors, we may further speculate that not only are they wide enough to allow for vehicular access, they may be served by a tractor beam crane that is projected and controlled from the fixtures above the door. Indeed, unless the landing gear is good at kneeling (and the side pods of the ship can be hinged up), ground access of any of the three lower doors would call for ramps that may not even be included in the structure of the ship itself and have to be provided by the port facilities - or then tractor beam assistance.
But kneeling landing gear is definitely an option, and the side pods certainly look as if they could be hinged (although only the outer pods have truly obvious hinges).
External stowage of cargo might be something that calls for these fancy prongs forward and aft; we see such prongs in many a pirate ship, and prongs or claws in Ferengi ships, all of which might be assumed to deal with externally handled loot...
Timo Saloniemi