If we are given a descent, say to be level 150 at Tiger, there are three ways to do it if a bit short of distance.
1. Speed up and dive the height off.
2. Extend the speedbrake and stay at your speed or slow down.
3. Speed up and extend the speedbrake.
Extending the speedbrake for extended periods is uncomfortable for the pax, so at this point I would usually aske if we are speed restricted. If not, I will speed up and keep it comfortable while fitting the requirements of the controller. If I am speed restricted, I will use the speedbrake.
This isn't a problem if you have lots of distance, and usually the controllers don't expect you to go down and slow down at the same time. However, when it is busy we often don't quite get the distance we would like. Lots of the controllers are helpful by saying "make the restriction at Tiger and then you can slow down". sometimes "standard speeds" helps as you know what to plan for after the descent. I have used the speedbrake before and slowed to 250 knots at the SLP just before being asked to fly 300 knots. Asking first makes it more comfortable and efficient and helps your situational awareness.
055166k - Non standard phraseology is a problem for things like clearances and defined things like take off etc. There is not a defined message for all eventualities, especially emergencies. If there is no defined message for speed restictions, then "standard speed" is plain english for what is required. Its not the same sort of "non standard" as we hear across the world which can be dangerous.