I came across this thread looking for some formal way to submit corrections to basemap data for (primarily) Light Grey Canvas, although others have the similar issues since I'm assuming the source data is the same.
I live and work on Long Island, NY and here's my short list.
NY Route 135 [Seaford-Oyster Bay Expressway] and NY Route 27 [Sunrise Highway] appear to be labeled as their "dedicated" names instead of their actual names. Regular and Vector
Suffolk County Road 51 changes names partway, and the point at which it changes from Center Dr S to Moriches-Riverhead Rd is incorrect. It should be approximately Lake Ave. Regular and Vector
Suffolk County Road 75 is not part of William Floyd Parkway. It is called Fire Island Beach Road. Not in regular light grey, but it's in others as well as the Vector
http://www.greaternyroads.info/pdfs/suffcr.pdf
Wertheim National Wildlife Refuge is incorrectly labeled as Southaven Park (which is north of NYS Route 27). Additionally Southaven (insert "County")Park is unlabeled (compared to ragular basemap). Vector only
https://www.fws.gov/uploadedFiles/WRT_Trail_Map_FINAL.pdf
Wertheim National Wildlife Refuge is incorrectly labeled as Southaven Park (which is north of NYS Route 27) in addition to it's correct label. Also indicate Southaven County Park. Regular only
Fire Island National Seashore labels sometimes occur on Smith Point County Park. While I believe Fire Island National Seashore does have a say in management decisions the land area is all Smith Point County Park. Regular only
https://www.nps.gov/fiis/planyourvisit/maps.htm
Westhampton House is correctly labeled on the Vector Basemaps, but the regular basemaps have multiple labels down towards Pikes Beach.
Thanks,
Mike