IMO CLI is not headless its command line , the QT interface is a separate application paired with the distribution and releases. I was in hopes this was going to be similar to the review I did on Moises's Android remote control for gridcoinresearchd as the reviews seemed that people did not understand that it was a remote control for the daemon and not local and remote and when you install gridcoinresearchd you can remote control it via the RPC port 9332.
Although it is good to periodically write a how to use your Gridcoin client for Linux newbs but the QT interface is not required for use of the client. I would assume you could use the QT interface by itself and remotely control a wallet say having it running gridcoinresearchd and the listen=1 rpcport=9332 and rpcuser=username rpcpassword=password along with rpcipallow=ip and then a separate machine just like Moises's Android remote control but use the QT5 front end remote for a daemon running on Linux remote or local ( firewall forwards if needed ). But again , its nice to periodically have someone post a " How to use your Linux installed Gridcoin client for newbs " post here on steemit/reddit or other sites since they get buried in the newer posts although if you just search Google for " gridcoinresearchd rpc commands " you can find the same info posted here from the Gridcoin wiki and much more " Gridcoin Daemon CMDs " along with running gridcoinresearchd --help.
So again thank you for your post , it's helpful to newer users as we are always gaining new users at different levels of knowledge so these posts are valuable.