The CSAT data, on a ticket level, should not be visible to agents by default. i.e. no banner and no possibility for an agent to access the individual feedback from a customer on a ticket unless permission to see individual CSAT is granted. (I am not referring to agents being able to see their own, overall CSAT score - overall scores are fine as long as they cannot break it down to individual tickets or access other people's scores by themselves.)

Do you think removing CSAT results from the ticket banner but keeping in the ticket events log would address your concerns?
As long as agents can access the events log no, because agents can still easily access the data - no difference to the current situation. It shouldn't be displayed at all on agent level access unless the permission to see CSAT is granted
Will those performing quality analysis on the tickets be able to find the CSAT data?
I don't understand this question - they will find it if they have access and are told where to look - no difference to now. Generally, I doubt that anyone working somehow efficiently would do CSAT analysis by looking at the banners of hundreds of tickets - you would run high level reporting and break it down from there. As long as the CSAT for each ticket is accessible for non-agent roles (or if permission is granted) and it can be accessed/ drilled down into via reporting then there is no issue.