I can see how the recent update has impacted your workflow, @ebricks. The ability to add time charges directly to an open invoice was indeed a valuable feature. You'll be glad to know that your goal is still possible. 

Please ensure you've selected the Billable option for the time charged to appear in the Suggested Transactions.

First, let's verify if the billable expense feature is turned on. Here's how: 

1. Head to the Gear icon, then select Account and Settings.
2. Click the Expenses tab.
3. Select the Bills and Expenses section to expand it, and check if the Make expenses and items billable is on.
4. Hit Save and then Done.
    

Afterward, check if you've billed your customer for the time charges. Once confirmed, let's open an existing invoice to add it.

1. Go to the Sales menu, then Invoices.
2. Open an invoice, and click Manage.
3. Choose the Suggestions dropdown.
4. Select the Suggested transactions.  
5. You'll see all the available time charges.
6. Add them one by one, then Save.
    

Moreover, to maintain accurate and up-to-date financial records, record any payments received so your invoices will be marked as paid.

While the interface has changed, your goal of adding time charges is still achievable. If you have any other concerns or questions, I'm always here to help.