Agreed, keep the CDA going as much as possible. There are several different altitude limits to separate you from low-level traffic/LC deps (westerlies)/heli-routes/to keep you inside CAS. Most controllers will give you as low as possible as soon as possible to both help you fly the CDA and negate the need for you to either level off or jump in requesting lower.
As stated, if your level is needed for separation from other traffic you'll probably get 'expedite descent' or 'vacate ..A now'
Regards.