How to make HistorySearchBackward/HistorySearchForward results be greyed out inline suggestion?

[Numan Zaheer Ahmed (Anutrix)]

When I press the key for HistorySearchBackward or HistorySearchForward, I want greyed out suggestions.
It should not automatically set current line as accepted.
I want acceptance to be explicit by right-arrow or tab press.
In other words, after pressing key for HistorySearchBackward, suggestions from history with cursor in same place should be shown.

The issue it is causing me is that it pressing backspace after above keys are pressed accepts result from history.
For example, let's say:

1. I typed git s and pressed the key HistorySeachBackward key. It suggested git s|tatus. With part after cursor greyed.
2. I pressed HistorySearchBackward key twice. It suggested git s|tash pop.
3. If I press backspace here(because I wanted to git log), it gives git |tash pop.
   I was expecting characters after cursor to be greyed here and show git |status or git |stash. With part after cursor greyed.
   Note: | is stand-in for cursor in this example.

Is there a way to do this?
Normally, pressing same characters(or backspace) as in inline history suggestions does not disable suggestions. Why is this disabled after HistorySearchBackward/HistorySearchForward key press?