Can our serums be used with a cryo-device?

Every claim with regard reduction and elimination (destruction) of fat cells is no longer considered as a cosmetic application and belongs so under medical practices.  (MDR 2017/745/EU legislation instead of Cosmetic EC 1223/2009).  
If you like you may consult the EC MDR legislation 2017/745/EU where you can find in ANNEX XVI : LIST OF GROUPS OF PRODUCTS WITHOUT AN INTENDED MEICAL PURPOSE REFERRED TO IN ARTICLE (2)  
The subjects named in this ANNEX XVI are considered as medical device !  
(4) Equipment intended to be used to reduce, remove or destroy adipose tissue, such as equipment for liposuction, lipolysis or lipo-plasty.  

In general, I do not see why a cream would be used prior to work with the device.  The temperatures needed for adipocyte freezing are between -8 and -12°C.  As our cream is containing all together about 48% of water it might not be a good idea.  I rather would use it than after the treatment.

But, how about that we claim to increase Lipolysis, both with NBE device and serum? Do we need to re-adjust anything in our texts?

The big difference is that they destroy the fat cell. The cells go in apoptosis which means that they are destroyed.  
We promote lipolysis. This means we promote the natural way that a fat cell burns fat to energy which is the same when you do sport training.  
However, you are right, we should try to avoid the use of the word lipolysis and start to promote body contouring or sculpting.