I just use a regular set of 12 inch tongs. I feed small rats all the way up to XXL rats without issue to my entire collection which has some strong feeders.
Feeding small to medium rats is easy with them. The XXL rats are more difficult but I doubt you'll be dealing with anything close to that size for a good while.
I just hold each feeder by the tail and offer. This makes the 12 inch tongs seem a bit longer because you add the length of the tail. I usually grab them about half way down the tail.
I would also advise against locking hemostats. It they're locked and the snake strikes hard it will either pull them in with the rat, cause the rats tail to pop off, or get skinned. I've had all of those happen with my tongs from a fast hard strike. I know if they were locked it would be an issue.
I was thinking of grabbing rat by the shoulder cause I feel like that's how most people do it. Do you think 12 inch would still work with holding on the shoulder/back for adult ball python? male