Well, I can think of speciall skill “Brannbolling” for bat - alternative to throwing. You “attach” some small consumable, and then with an alternative attack you send it flying with high velocity. Accuracy and range are directly tied to base throwing and it’s related skills. Due to higher velocity, arc is more flat and because it’s hitting the item, accuracy is halved.
Also, item “Small fuel cell” becomes mechanically “contact grenade”.
Handle would be modded for better grip (stamina and swing speed)
The head is studs, nails, weights: studs shapes bat into Kanabo of sorts. Adds a bit more damage to “detachable” parts (darkened in IR view); Nails - crit hits into internals; weights - adds more chance to stun, slightly adds overall damage with consuming more stamina (quick heavy hits, hammer need time to wind up).
About hammer - “tenderizer”, “horsemans pick” and titanium heads. See studs and nails for bat resp. Titanium head is lighter than steel so less stamina drain/faster attack charge at cost of slightly less damage.
Better rubber grip can slightly add up range.