cru_recently_visited and cwd_property needs denormalization - causing invalid primary keys warnings

.A support case is getting too-long primary keys because that table is using 3 nvarchar columns as its keys. That's terrible - this table should be normalized.

username column = should be a user id (but I do remember valid reasons for this - mostly because we didn't have time to fix our FE vs cru user management discrepancies).
item type column = should 100% be a recently_visited_item_type_id foreign keyed, if you like, to a recently_visited_item_type table, not an nvarchar(80)
entity_id = should be an actual id, not an nvarchar(255)

This problem will affect every user trying to migrate to SQL Server. However, it's just a warning - it isn't causing the migration to fail as I originally thought.