I did walk on the Esplanade, depending on where along Storrow Drive you consider it to start. My walks are getting longer (6.5 miles each), which will let me get to more places, including further down the Esplanade.
Here's the detail of Back Bay (including this morning's 302nd walk which took me to the corner of Beacon and Arlington): https://imgur.com/a/FqQmFNf
This is interesting b/c the esplanade is a pedestrian park with some beautiful water areas and bridges, its prime walking area.