Clicking the improve button on a suggested edit can lead to a situation similar to this one, but in somewhat of the opposite direction. Consider the following scenario:
- Post receives Suggested Edit 1
- User A loads suggested edit queue that contains Suggested Edit 1
- User B and User C approve Suggested Edit 1
- Post receives Suggested Edit 2 (because Suggested Edit 1 was incomplete, shame on User B and User C)
- User A clicks improve on Suggested Edit 1
- User A sees improve edit box with contents of Suggested Edit 2, instead of the expected Suggested Edit 1
This is pretty disorienting for User A, since they clicked improve because of problems with Suggested Edit 1 and are instead seeing (without much indication) Suggested Edit 2 in the edit box. If they don't realise this, they could also inadvertently mark Suggested Edit 2 as either helpful or unhelpful based on what they saw in the diff from Suggested Edit 1, which might be incorrect.
The system should be paying attention to which suggested edit User A actually clicked improve on, so that it can warn them that a decision has already been made on the suggested edit in question. This could take the form of redirecting them to the new suggested edit, or displaying a message about going to the post to make additional changes like it does when you attempt to reject an already-approved edit.