How many tweets can a thread have, and does numbering count toward the character limit?
A thread you create in Circleboom can have up to 25 tweets.
Character and media limits in a thread
Each tweet in a thread has its own limits. The character limit X allows for your account and the media limits apply to every tweet separately.
Does numbering count?
Yes. When you turn on Auto Numbering, labels like "1/5" are added to each tweet and count toward that tweet's character limit. Leave a few characters free in each tweet for the numbering.