I suspect it depends on what the purpose of those weapons is:

Consider, for instance, some kind of high-orbit defence platform with regular resupply. That can afford relatively wasteful practices, although, even there, throwing heatsinks overboard and FOD'ing it's own orbital track seems unwise.

Perhaps they'd settle for a simpler option of using a water heatsink and just spraying the stuff overboard - or the sublimation system the Apollo spacesuits used.

Conversely, some kind of spaceship operating far from support might not want to dump it's water overboard every time it engages targets, so might prefer to maintain a stock of dedicated heatsinks or just run very large radiators to dump the heat without requiring any consumables at all.

Visually its kind of a neat idea, space warships ejecting maxxed out heatsinks like empty mags and swapping in cool ones.