Cracks are visible

Has made an object and has smoothed his keen edges by means of the Variable radius surface blend tool…

But if to approach an object (the lower part which I have smoothed) – I see it:

Merge of edges not full (cracks are visible). How to correct it?

Washy you see are rendering mesh artefacts.

https://wiki.mcneel.com/rhino/meshfaq
https://wiki.mcneel.com/rhino/meshfaqdetails

Try joining the surfaces - it will regenerate rendering mesh. Perhaps it will look better.