I don't think I've ever reused names or designs, the latter especially given they were fandom. But I usually recycled personality traits, quirks, mannerism type stuff as well as some fashion choices for characters especially one that had distinct "looks" if that makes sense.
I've definitely done this ^ sometimes it's a recycled cliche other times it's the way a character impacts another from a rivalry, to a loss or the motivator or obstacle to the protagonist
i think the most I've ever done with repurposing a character was slipping old oc's or unused oc's into the background mostly for myself. never in a way that they stand out but having them assume those small roles like barista at the protag's favorite coffee shop or rando that gets knocked over in a chase scene. it's likely the only way my one large ensemble cast will ever live on till i find a way to rewrite their story