Equipment loaded on craft (e.g. Triton) take base storage space. This is not entirely realistic, but doing otherwise might have implications all over the place. However, looking at the code, there seem to be some exceptions or slightly different mechanics (e.g. missiles being armed on a craft aren't counted).
My main question is, is there a handy way (as a storage space management practice) to check how much storage space various items on craft are taking? Base information "Stores" screen does not include the stuff loaded on the craft, so you can't for example sort by the storage taken to transfer/sell unused stuff. "Grand total" screen does show equipment loaded on craft, but also equipment on other bases.
For base storage management perspective what appears to be missing is a separate listing (or listing as part of regular base storages) of all items taking space on a specific base. I wonder if the regular base stores screen should actually include equipment loaded on the craft as it's counted anyway. Or alternatively, maybe the base information should at least include a single line for every craft, like "TRITON-1 including equipment", summarizing space taken on all equipment loaded on the craft. That way, the total amount of space on base information screen taken would more closely match the one actually taken (except for transfers and other adjustments, which could also possibly shown as a single line, like "items being transferred" or some such).
I guess you could remove everything from the craft, check the screen, and then re-add everything back. But re-adding everything back on the craft manually could be rather tedious if you have to do it regularly.
