Adding my +1 into this feature. If not setting it based on trust level, just the ability to turn on and off the setting for DMs vs public channels would be helpful, instead of having it all under one yes/no toggle.
It’s not planned yet, but I think it’d make sense to convert the setting to match others that let you configure with groups have a given privilege, e.g. chat_uploads_allow_groups.
As long as the setting doesn’t prevent pasting the markdown you copied from the composer, where you uploaded the image, it doesn’t really prevent users from using images in chat.