It would be nice if you would remove the line that states that the right side of the 52 degree triangle points to the Capitol Building.
"Despite your attention on the accuracy of some of the details - and I would expect this - for me, what we see here in the overall picture stands"
For you and others who do not pay attention to these details. Like in your figure 4 on that page where you depict Penn Ave as being straight from Georgetown to the CB, and which you label as 23.5 degrees.
If you extend the line of Penn Ave past the WH to the southeast it crosses the N-S line of the CB well below the center of that, meaning that the section of PA between the WH and CB is not aligned as the northwest section is and does not deserve to be labeled as 23.5 degrees. But if it works for you and your readers......
I would go on but I have already posted web pages about this that you can read, I hope.