One of the FFLs I deal with frequently has not yet adopted the eForms system because of the fact that paper applications offer the chance of a correction letter, whereas an error on a submitted eForm would result in a denial and a requirement for a complete resubmission.
However, that may be changing, at least where some examiners are concerned.
Several members of the NFA group on Reddit have shared images of emails from examiners allowing documents (such as the Form 23) to be corrected via the eForms system rather than disapproving the entire application and forcing it to be resubmitted.
I do not know yet if this is limited to specific examiners or reflects a policy change for the entire agency. Regardless, those who have submitted eForm applications should watch their emails closely since the emails that have been shared so far seem to limit the opportunity for correction to a 48-hour period.