There are times and places where selection of flap 1/5 at 235 kts cannot be avoided
- can you tell me a few? I'm intrigued.
Of course you can use any part of the aeroplane up to its 'limit' (and, indeed, beyond) but there are very good reasons for not doing so unless you are in dire straits. It is not up to Boeing to change procedures - they are not flying the aeroplane.