Guessing that the DeLorme and Streets & Trips users have issues with GMaps' limit of 10 waypoints? I default to GMaps (and save the urls in text files) despite sometimes having to break a long day into 10 or more individual routings. Actually the breaks are kind of useful for gauging how close I am to the predicted time. The lines on the sheet I posted correspond to the ends of each partial route, with the time Google predicted "without traffic" there to let me know how far ahead of or (usually) behind ideal I happen to be.
How could you guess
Actually Delormes maxes out at 100 waypoints. I discovered this 5-6 years ago when I was plotting out my Lincoln Highway in Iowa revisited trip.
Tim Brown used GMaps for his Cincy Roadmeet itinerary, back in 2020, and I wasn't fond of the multiple layers he had to use to cover his trip, and that was just one day & one city.
Back to my DeLormes map program, it does allow one to break up multi-day travels and allow one to know how long one has to go before reaching their destination (assuming one has a GPS unit attached to their laptop). One can manipulate the pre-programed time (i.e. how fast one can drive on various roads), though I find myself normally doing better on time than what DeLormes originally predicts....unless I take more stops than I originally planned.
Maybe you can start a new research project, for my alma mater, for a new map program that is more flexible than Gmaps, but more portable than the old DeLormes & Streets & Maps programs.
Present your research proposal at the 2023 Ohio Roadmeet (wherever I decide to hold lunch at, in Columbus or Delaware)