Eyes can focus on a limited area of high resolution surrounded by a large area of lower resolution. However, areas of strong contrast such as reverse video are still visible in low-resolution areas. Blinking items are not only visible, but will draw the eye to them. "Status" displays should therefore change as quietly as possible so as not to draw the eye away from the text under edit. For example, it may make sense to place such status areas on the top part of the display if insert/delete line operations cause visible motion of the bottom part.
There were two turning points for me in my journey. The first was a chance conversation with one of our accountants when I was complaining how slow it was to keep having to flip between worksheets to see different bits of data. He introduced me to VLookups and a new world of possibilities opened up. I found that I need never have huge paper accountancy pads (remember those?) and a calculator to produce a production plan again! Suddenly, I could produce my plan in 15 minutes, rather than the day and a half it used to take. I began delving into other features of Excel, and finding ways to incorporate them into the planning "system" I had created, and remember this was back in the day when the internet hadn't been invented! Through trial and error, I refined my Workbook until I could chomp through days of work in seconds, and what's more, using these powerful features of Excel, I could optimise our production runs to get more output from the same working week, something that had never been done before. Promotion soon followed, and I became the "go to guy" for anything Excel related. This was the 90's.