There was some work done in the past regarding how much time it saves renaming characters for a human. For a TAS, pretty much all characters are worth renaming to a 1 character name due to the fast that you can go crazy with the inputs. The way the game works on letters is that every frame, the game draws a letter, so if we compare by how much time the name is being drawn into text boxes vs how much it takes to rename your character with human inputs, we can calculate how much time it saves.
The math was being done below. Conclusion is every characters is worth renaming for any category.

The only instance where it is not worth it is : 
– Shadow (Only If you are racing Kefka At Narshe)
– Mog
– Gogo!AhyT3NHpHVTfgcBI-AQ0tzglomEiHw