Uploading images question - re: Compression

I am using a forum which uses discourse, and was talking to my admin about uploading images in threads wherein some images are being uploaded in near full res (8 mb) and others are being compressed so much that you can’t zoom in to see detail. He explained everything we both know about storage and discourse compression.

However he said that there might be a custom workaround where he could allow certain accounts to not have the limitation, or certain threads. Something like that.

Does anyone have any ideas or solutions without having the admin allow all accounts to upload up to 8mb (or more, whatever the max is). Where he could, say, let some accounts or threads not have the limitation?