This is a very important topic, working on my CSP now and i stumble upon many problems with prestashop.
It is very hard currently to implement content security policy.
Too much inline styling even out of the box.
The default ps google modules do not allow implementation of server NONCE oob (some official docs from google here)
After reading this here i still think there is much to be done in terms of security. Security should be a requirement, many modules and themes are probably breaking prestashop's security. And even outside the scope of third party modules, some default prestashop modules still trigger CSP warning reports due to inline of javascript, like the google analytics code and the cart module.