Hi @LordKavanha, yes deleting the project folder is the current method for removing projects from the UEFN Project Browser.
Edit: Spoke to quickly, sorry 
You can delete projects locally on your machine by deleting the project folder. However, since the project also “lives” in the cloud UEFN will still “think” that the project exists. Sorry for the confusion. We’ll be adding the ability to remove projects from the cloud in the future.