error - the LAST thing you should do if you are 'at high level' and encounter an overspeed is 'zoom up' since you will worsen your performance margins by climbing..
I am confused by
If able to give up altitude, which widens the margins, the better.
- I assume you mean descending, which will further increase your speed.
As safetypee says, forget all about 'coffin corner' in commercial operations - you will not be near it.
You started by talking about 'turbulence' and needing to descend - yes you will if you need to retain sufficient 'spare' performance in mod/severe turbulence. In normal ops, however, there will always be sufficient speed margin for you to descend without an 'overspeed', and even if you do, as JF says, no 'biggie'. As sp says, be gentle!