Active Campaign DB maintenance

We have the server based Active Campaign version: 5.3.6 Build 2 (i.e. we host the software on our own server...not their SAAS services). . We need someone who is familiar working with the AC database to: We have the server based Active Campaign version: 5.3.6 Build 2. Need to: A) Review and optimize as necessary DB, as currently upload/update of 16,000 records, takes 10 hrs+ B) Reset ‘Bounced’ subscribers to zero in DB for List=_Sales Working and/or remove past bounce records. There are 6,000 subscribers, previously bounced-out due to our IP getting on a blacklist, which we want to remove as 'Bounced'. Our Sys Admin says that “There is no separate database table for bounced emails. All emails are in a single table called em_subscribers. This table has columns call bounce_hard and bounce_soft which is use to identify if the email has bounced. I have set all the emails you have sent to as 'not bounced'. But, after Sys Admin did that, when we try to upload/update the previously bounced records, Active Campaign still rejects them, as having previously ‘bounced-out’