We specifically would like to be able to see the Salesforce Comments Tab data/comments, to be visibility the the 'All Activity' Tab within a JIRA Issue.
Typically this Tab would show you "All' pieces of information, but in this case it does not.
Would be even better, is to just inject the Salesforce Comments directly into the regular Comments field in JIRA. Given that this is functionality that is already available in the JIRA API I think that this should be pretty straight forward from your stand point.
Reference Here: https://developer.atlassian.com/jiradev/jira-apis/jira-rest-apis/jira-rest-api-tutorials/jira-rest-api-example-add-comment
Also, I understand that this might not be functionality that all customers want, so an ability to manipulate the functionality to act in a 'classic' mode (like that in place) or a new advanced mode as suggested.