CreamCloud0
Hero
i think artificers should just inherently be able to double the duration of any transmutation spell that they cast on an object and don't need to maintain concentration on it (they can still drop it at any time they wish though) they're THE archtypical 'enchanter'(WTH are spell schools doing? lol) class, there's precedent for this type of ability in the mark of making human who gets a 1/LR casting of magic weapon that lasts an hour without concentration.