Bulk Editing Client Records ... Seeking an App or Addon that can help me achieve this

Modifying your client's records based on certain conditions is a great functionality, LisaC16.

As of the moment, the option to bulk edit your clients' records is unavailable in QuickBooks Online. In the meantime, you'll want to visit our marketplace or head to the Apps menu to explore third-party providers that best suit your business needs.

While we're unable to recommend which one to use, you can enter a specific keyword or select a category to streamline the search process.

1. On the left panel, click Apps.
2. Go to the Find Apps tab.
3. Enter a keyword in the search bar.
   

I can understand how convenient to have this option for your business. With that, I suggest sending feedback to our product developers so they can review it and might consider adding this in our future updates. Please refer to the steps below:

1. Go to the Gear icon.
2. Under Profile, select Feedback.
3. Enter your suggestion.
4. Hit Next.
   

You can track your feature requests through our QuickBooks Online Feature Requests website.

Feel free to reach out whenever you have inquiries or issues related to our products. I'm available at any time to assist.

@LisaC16 

You can export your client list data to XLS, modify it and reimport back into QBO. You may need to remove the list before reimport it back.

https://get.transactionpro.com/qbo

Use a backup restore app to lower any risks before connecting the apps.

https://partnerwithus.rewind.com/quickbooks

THANK YOU, Fiat Lux - ASIA.  

That's the sort of specific information / lead I was hoping for!

We do already use Rewind, even though our Accountant / Intuit Advisor said it was overkill and not necessary.  I disagree with her. I'm too paranoid to trust Intuit / QBO Tech Support to help restore backups in a pinch - based on past experience of often having a hard time being connected with a Representative that understands the more complex aspects of QBO. Rewind is relatively inexpensive compared to potentially losing hours and hours of my time dealing with trying to get QBO Tech Support to help me.

Today, I've looked at the Transactions Pro link you provided, and will save this information for a bit later - after our busy season - when I'm ready to attack this problem more.  Currently in "gathering ideas" stage so I can work on it this winter if I don't get to it sooner.

I do note that, yesterday, before I posted my question in this forum, I did a quick chat with the  Transactions Pro website, and the person answering the chat would not or could not confirm if this tool would achieve my goal - they insisted I had to give them my phone number so a rep would call me to confirm if it would work out.  That's not something I was prepared to get into and so I told the chat-rep I'd pass for the moment.  Basically trying to force a potential buyer to provide a phone number (and therefore to likely then become part of a marketing list) feels sort of shady in this day and age of SPAM being out of control.