Not sure what your setup is but in general 99% of the time this type of feeding issues are related directly to husbandry and stress.
Assisting or force feeding or tube feeding is not something you want to do long term as it is very stressful, what you want to do is see if husbandry change can be made so the animal start eating for you.
The more you will tube feed or for feed this animal the more it will be stress, the more stress the less likely it is to eat on it's own, the animal knows how to eat.
There is no target weight there is healthy look so this is what you goal is.
Offering fuzzies and pinkies could have been an issue as they are to small even for your BP and may not be recognize as prey but what I am interested in is your setup can you give me a run down on your setup, tub size, hide type and size, temps, substrate, do you handle this BP other than for feeding.