Reverting back to original s3 bucket policy. will it cause problems?

I would like to test out new s3 bucket policies where I deny public access to a certain folder (make private)

I am wondering if I will encounter any issues if I make a folder private and then attempt to revert back to keeping it public. Will I have problems switching between the two states.

I use CarrierWaveDirect to upload images to the folder that I want to switch states. Currently the folder is public, but I need to make it private so that anonymous users can not read or download the high resolution images.

However I still need to keep a connection open with the admin IAM credential so that the web app can upload files to the private folder and then read them for image transforming using CarrierWave & MiniMagik