Pyro,
I don't have a personal stake in the answer, but is it possible that through a translation quirk, the manual *really* meant that you shouldn't change the flap position above 250 and it shouldn't be at full above 250? "operate" can mean "fiddle with the switch". Case in point is the F-15E which has different speeds for max allowable with the gear down and max speed where you can raise or lower the gear. You can fly quite a bit faster than gear "operation" speed with the gear down if it's put down while still below the "operation" speed...
The same goes with the automatic flap retraction in the F-15E. The flaps should not be lowered when above 250, yet if they're left down they will (should) automatically fully retract by 300 knots.
If I recall correctly, one or more variants of the little cessnas (150, 152, 172) also has a flap rule where you can have the flaps down up to a certain speed but the flap "operation" speed is somewhat lower, interpreted as meaning you can't move the flap lever until you're below that "operating" speed. It's been 18 years since I was taught that rule and it's not even the same in all year models of whatever type it was, but it's another area for a discrepancy to arise.
Anyhow, since I've come across that discrepancy a few times in RL, I thought I'd bring it up to see if maybe there's a translation or flight manual interpretation issue behind this particular FM quibble.