Thanks for dropping by in the Community, @crispyhexagons

QuickBooks Online (QBO) mobile app lets you access your business data instantly. However, selecting a form style or a template form from your mobile is currently not available. You’ll want to log in to your account via a regular web browser to create and choose a form style from there. I’d be glad to guide you how:

1. Go to the Gear icon.
2. Select Custom form styles.
3. Click the New style drop-down and select Estimate.
4. Go to the Content tab.
5. Select the Table section.
6. Uncheck the box Rate and Amount then click Done. 

To apply the form style, create or open an estimate. Click the Customize option from the bottom of the estimate and select the template you’ve created.

For more details about this process, you can refer to this article for reference: Customize invoices, estimates, and sales receipts in QuickBooks Online.

In regards to adding a tax for each line item, I suggest looking for a third-party app that has this option. You can go to the Apps menu from your QBO account and browse an app from there.

I appreciate your thoughts and idea about having this feature in QBO. Rest assured our product team is always looking for great ideas from users, like yourself, when deciding how to enhance QuickBooks.

While I can’t provide you a specific date as to when this feature will be available, I suggest checking our QuickBooks Blog page for reference. Here, you'll stay updated on any news and enhancement about QuickBooks.

Let me also add this article that can guide you accurately in converting your estimate to invoice: Convert an estimate into an invoice in QuickBooks Online.

Know that you’re always welcome to leave a reply in this thread if you have any other questions about estimates. I’ll be around ready to answer them for you. Keep safe and have a great day!