Ok, the collation fixes have now been implemented in latest CB build release.

For new installs _comprofiler will match its collation to _users. All other core CB tables will match their collation to _comprofiler. Plugins initial collation will match _comprofiler.

For existing installs within CB > Tools running "Check Community Builder Database" will scan for collation issues which you can then use the button it provides to fix. Note this only checks TABLE collation. It's too heavy to check collation of every column of every table so if you've a correct table collation, but wrong column collation you'll need to fix that one manually.