Can I change all LoginSecure Content modules in one go?

Yes, this is possible but only when you set up the extension to inherit all settings from your template's stylesheet. 

If you use custom styling then you have to adjust this per module because each module is standalone.

KB Article: https://loginsecure.eu/helpdesk/knowledgebase/view-article/82-can-i-change-all-loginsecure-content-modules-in-one-go