Using nopCommerce 2.30, when adding a new product there is no length attribute presented to the SEO Keywords textbox ("metakeywords").
If I exceed the 400 characters limit that is defined by the entity definition (and the database column) then I get a nasty error:
Exception: Property: MetaKeywords Error: The field MetaKeywords must be a string or array type with a maximum length of '400'.
So it looks like validation is occuring, but the @Html.EditorFor method is not using the validation data to set the HTML textbox's field length to 400.
I haven't checked to see if other fields are affected, but I would guess that they are.
Thanks,
Matt