You probably won't get many requests for this because unless someone's encountered it in some of the big non-industry proposal programs, you wouldn't know how valuable it is. In most of the major cloud proposal sofytware (PandaDoc for example), you can not only see when someone opened your proposal, you can see how much time they spent on each page.
That allows you to see how effective your overviews are, if people are looking at your proposals or just jumping to the bottom line etc.
That in turn allows you to improve based on those metrics.
Thanks for considering.