As for availability...this came into my email today:

"Issue Number: Tax Tip 2020-69

Taxpayers will soon be able to file amended tax returns electronically

Later this summer, for the first time taxpayers will be able to file their Form 1040-X, Amended U.S Individual Income Tax Return electronically.

Making this form electronically fileable has been a long-time goal for the IRS. It will greatly benefit the tax professional community and taxpayers.

The new electronic option will allow the IRS to receive amended returns faster while minimizing errors normally associated with manually completing the form. It will also provide the IRS with more complete and accurate data to help customer service representatives answer taxpayer questions.

When the electronic filing option becomes available, taxpayers will only be able to amend tax year 2019 Forms 1040 and 1040-SR returns electronically. In general, taxpayers will still have the option to submit a paper version of the Form 1040-X and should follow the instructions for preparing and submitting the paper form.

Whether an amended return is filed electronically or manually, taxpayers can still use the "Where's My Amended Return?" online tool to check the status of their amended return."