As you’re already using a Pi, I would look at UGS: Universal Gcode Sender - http://winder.github.io/ugs_website/
Also Chilipeppr, Octoprint, and SourceRabbit are all grbl-compatible.
http://chilipeppr.com/grbl
https://www.sourcerabbit.com/GCode-Sender/
I’ve been using Chilipeppr/TinyG with Serial Port Json Server https://github.com/chilipeppr/serial-port-json-server/releases for CNC for quite a while over wireless/Ethernet.
But, WiFi ain’t WiFi - mine is fast and reliable with high-spec routers/APs running at a high rate. The kind of gear an isp throws at you may not be up to the task.
Depending on your toolchain, you can design, CAM, send, all from one app, with your control software monitoring a hot folder for incoming jobs.
Using a ‘hot folder’ is tried and true network technology that’s been used for at least three decades, to my personal knowledge.
Without wanting to disparage the developers of GroundControl in any way, there are better tools out there that do the job.
Out of choice I use chilipeppr, but the disadvantage for me is it’s cloud-based - we don’t have the best adsl connectivity here in the swamp/jungle. I have gotten by that by running a local iteration, but it isn’t trivial to set up.
If you have reliable internet access - first-world speeds, not the 1.5Mb I get on a good day - I would absolutely use it. John Lauer, the developer, would welcome a Maslow-specific workspace.