I don't recall seeing posts on this topic.
I discovered RSE/RSP late, in their last year of development.
In the last few months, the two were based on common code, with RSE simply being more restricted in functionality (especially regarding ability to generate and save settings for future use).
It happens though that settings created and saved in RSP can be copied into RSE folders for use there too. "Appearances" can include color balance and other adjustments many may think are not possible within RSE. Thus, if you have a friend with RSP, he can save your favorite setting for you and send them back to you for use in RSE.