Rhino surface tolerance

Can anybody explain how manage this: after joining two surfaces tolerance changes like I show on this images:

Read here:

It should be done by tolerance settings in project settings, but it is not enough… I use Rhino for Mac. Cann’t say much about Windows version but may be it is the same. I’m new in Rhino, I just start to learn it and need some help also.

All important’s

Thanks so much - I have find per object mesh display setting and now understand how it works

Ok, a lot of fun while modeling :wink: