Or maybe I’m misunderstanding how it’s supposed to be used. I’m tokenizing my whole text and then dividing the tokenized text into chunks of size 126 or less (all but the last chunk are of size 126). Then I send the list of chunks into the tokenizer:
batch_encoding = tokenizer(text_chunks, add_special_tokens=True, padding='max_length', max_length=max_seq_len, is_pretokenized=True, return_attention_mask=True)

What I want it to do is simply add the special tokens [CLS], [SEP], and [PAD]  (if needed), and then turn the wordpieces into input_ids. Instead it does another tokenization with the wordpieces:

[‘ka’, ‘##vana’, ‘##ugh’]

is turned into

[‘ka’, ‘#’, ‘#’, ‘van’, ‘##a’, ‘#’, ‘#’, ‘u’, ‘##gh’].