Hello,
With 3 same items, you will have 3 serials ; but you won't be able to specify a different name via a custom field.
fill a form with 3 name fields and each ticket generated should have 1 of these name on it
You can develop a custom plugin in order to perform such action ; it won't be easy due to all the constraints you will face (refuse the modification of the quantity, link the quantity with the number of lines/names in the custom field ; otherwise it will generate some misunderstanding and frustration for your customers)
At the end, you custom development should provide the order items are separate items with each one name ; so it could be process by the plugins, like HikaSerial pdfseria/attachserial.
The best approach is to use item custom field and let the customer handle its items in the cart.
Each item will have its own name and the customer can remove, replace like he wants without any kind of frustration.
If you want more details, I recommend you to open a new thread in the HikaShop section of the forum so the HikaShop support team will be able to guide you.
Regards,