Glad to have you join this forum, Chris3343. I've come to share input when converting estimates to a purchase order in the new layout experience.
As QuickBooks aims to provide enhanced layout preferences and satisfaction to product experiences when performing customer-sales and vendor-expense transactions, converting estimates to a purchase order isn't still available in the program.
For now, you may want to consider migrating back to the old classic form if you're using QuickBooks Online Plus and Advanced subscriptions. This way, you can efficiently manage and accomplish tasks seamlessly. To help you do this:
- Go to the + New icon and select Estimate.
- At the top right of the form, click Old Layout.

Additionally, you can browse this reference for more added information about the updates and features of the new layout experience: See what's new with estimates and invoices in QuickBooks Online.
Moreover, you can add specific customizations to your sales forms to achieve professional-looking forms when invoicing your customers.
I'm always available in this thread for any additional queries about the new layout experience and QuickBooks updates. Feel free to reply to this post, and I'll make sure to get you covered. Keep safe!