RE: change cursor type when idle

[Drew Adams]

    Most often a long idle period means that I started reading
    displayed text,
    and don't need to see the cursor.  I use `avoid.el' to move the mouse
    pointer away from text, and like to do the same for the cursor.
    So I rather like to hide the cursor after an idle period than to make it
    more visible.  I see no other way to tell Emacs to show the
    cursor when need
    than to press some keys.

Maybe in your case you should hide the cursor when idle, and bind a key to
show it (big, bright, and blaring).

The thing about the cursor getting lost in dense text, and your not wanting
to see it when you read text, are complicated by the existence of multiple
windows/buffers/frames.