I'd suggest that that would be best left as One Shot - similar reloading times were given for many of the one shot rated japanese ships but various experts pointed out that although that was a reload time, it was not something that could feasibly be done in combat so in practical terms the torps in question were one shot.
As far as the ship which carried a centreline torpedo mount (Stier) I would agree with you and will edit the entry to that effect. The other ships however, carried their tubes at the waterline (and, in the case of Widder, actually below the waterline, according to Duffy) and inside
the hull. I feel this would allow reloads, however slow, in combat where the destroyers and cruisers you mentioned may not be able to achieve the same thing as the crew was exposed and, to say the least, a tad distracted during the reload process. I also rather suspect that, firing every fourth turn, the chance of the ships reloading and relaunching before they got sunk by the warships they would be facing would, to a great extent, render the question moot
Thanks for reading the entry and the feedback