1. Proof Comment box: what is the max # of characters it holds?2. Change/Replace Feature: Is there one in Proof HQ - how do i take a 140 page doc and change 50 random instances of 2020 to 2021 yr

#1 - I've never reached a limit and haven't had any complaints about a limit

#2 - you can't do this in Proof, you have to make a comment for each change you want to indicate. Instead I would recommend you make a single comment for the designer for them do the search and replace in the native program they are using ie InDesign.

For #2, our proofreaders use the Search Text In Document tool (not search text in comment tool) and then you can use the markup tool to mark each instance of it and it is all connected to one comment box. My proofreaders love it, but my designers hate it, so that is something your people will need to work out. ;)