Names of parameters may benefit from not being abbreviated
I know this is nitpicky, but I think good naming is worth a lot of thought.
A lot of the API seems unhelpfully abbreviated to me, especially since lighting is designed so that you don't have to handle manual details like dataloaders more than necessary.
Names like tng_dataloader don't seem to buy anything over train_dataloader or training_dataloader since they're written only once and read many more times. Really, tng could be replaced with training or train elsewhere too.
data_batch seems redundant, I think it could just be called batch since in context it can only represent data anyway, and batch_nb is already a separate argument.
Describe the solution you'd like
Rename. The library is still in early days.