Im not sure if this is the kind of feedback you are looking for but...
I'm a Grant and naturally looked there first. I noticed there were several tartans that were missing. Most notably the "Grant Champion" Tartan, and the "Grant Piper" tartan that are based on the 2 paintings by Richard Waitt in 1715 (?). There are also several versions of the Grant of Achnarrow tartan that are not represented. Since these are pretty rare and would probably be a weave as needed tartan, it may not be in many mills regular production line. So perhaps that's the reason they arent there? At any rate if you just look up "Grant" on the STA Index you will see them. Thanks for allowing us to offer opinions.