spans.manual slow preformance

Hello, When I try to run prodigy spans.manual blank:es --label DRUG,DISEASE -C the performance is very slow compare to the tokenized option (without -C). it is very slow, it takes like 5 seconds to annotate 1 span. I also notice that every annotation take 100% of my CPU. which does not happened when I don't use the -C flag.

Why is this?

How long are your documents and are you able to split them up into smaller chunks, e.g. sentences or paragraphs? If you're annotating single tokens, the UI will need to create an element for every character, so depending on the length of the documents and the machine/browser, it's currently possible that the rendering ends up a bit slow.