This bug affects Zoomtext in a significant way, has been recently reported by the vendor and is within the Windows push, hence I am assigning a priority of 1.
Steps to reproduce:
data:text/html,<input size="50" maxlength="30" value="Very very very long piece of text">
1. Place the caret at the end of the input field.
2. Call IAccessible2.get_characterExtents(IA2_CARET_OFFSET, 0).
3. Observe that the X coordinate returned is outside the screen.

Cause:
1. scrollX and scrollY accessibility attributes are not present on the input field in the accessibility tree but are present on the div container that is at the root of the shadow DOM inside the input field. This means that they are ignored by the existing get_characterExtents logic in BrowserAccessibility.
2. The scroll offsets on the div at the root of the shadow DOM are not properly updated but scrollX stays set to 0 even after moving the caret left / right.