Editable character body model: What way to go for?

Hello there,

I am a bit of a newbie with Unreal Engine and I hope the more seasoned among you would be so kind to offer me a bit of advice.

I am trying to go for a blueprint based - in game - character editor, in which the player customises:

a) length and

b) thickness

of a “sausage” using the “bones” of said sausage.

Below is a sketch visualising the editor.

I am currently trying to achieve this using splines, how should I proceed? Is there a way to make them editable in game? Is this the easiest way to achieve this? Are there better ways to do this?
Thanks for the help, it is really appreciated!
Have a nice day!