Currently in Qiita we only support phylogenetic analyses with close reference because we need to create a new phylogeny with the combined datasets when using other techniques, in this case deblur. Note that this is something that we are actively working on and should be available soon in the system.
Now, you can combine your deblur bioms from all studies and preparations and then download the resulting files to continue analysis in your local machine, suggest checking out these posts: