The truncation is whichever of DC_MAXOBS_WEBEDIT and DC_MAXCELLS_WEBEDIT
binds first, and for a wide table it is the cell cap - floor(cells/columns)
rows, potentially far below the row limit. The hook page named only the row
cap and quoted its 250 default, so a hook author would check the row count
alone. Same correction in the two-rule-sets page.
getdata no longer refuses a selection over DC_MAXOBS_WEBEDIT or
DC_MAXCELLS_WEBEDIT - it serves the rows within the limit and flags the
truncation against the table name. Update the option reference and the two
developer-guide pages that claimed the edit screen stops with "Table is too
big". The hook page also carried the old 500 row default.