Liscio's e-signatures are per document, not per signature. For example, if two forms are combined and uploaded as a template and sent to two users, this will only count as one document. Please note that forms sent not including a signature block still count as a document used (for example, a questionnaire sent that needs to be filled out, but does not need a signature).
KBA (Knowledge Base Authentication) is typically only used when sending an 8879 for signature. To use KBA on an eDoc you're sending, check the KBA box when creating the eDoc. Checking this box will use 1 KBA and 1 eDoc.