These are cool. For anyone in the market for a vinyl cutter I would recommend against Cricut though. Very cloud-subscription-user-hostile software that tried to limit the number of times you could use the machine you bought unless you had a subscription. I have a silhouette and control it with a plugin for inkscape and its great.
what's good? have been shopping for something to cut medium EVA sheets. seems like brother scan N cut is most likely to work with SVGs + linux, but can't handle anything past 2mm. siser juliet + silhouette get recommended too but I think both rely on proprietary software
laser cutters seem better on the software side, but more expensive, less safe? (and also not safe at all for vinyl)
The silhouette software is proprietary but I am using Linux + inkscape + https://github.com/fablabnbg/inkscape-silhouette which works perfectly (except I can't get the Bluetooth to work but that's probably a me issue). It's less user-friendly (but more power-user friendly) than the official software and doesn't have all the templates and ready-made designs but that isn't a problem for me.
I would like to get a laser cutter at some point but that's a completely different beast. Don't get a cheap ali-express one that is not enclosed if you value your eyes. You will also need ventilation for a lot of materials if you value your lungs. In comparison, my silhouette is a simple thing I can move around easily. It's also able to plotting, engraving, embossing and foiling with the right add-ons
I like my Silhouette Cameo, which I use from Linux and Windows with Inkscape + the silhouette plugin. However, the maximum thickness that the latest machine can cut is 2mm, and it seems that is also the maximum thickness that the Circuit Maker 3 can handle. So, you probably do want a laser if you want thicker eva than that. In my book, the best choice is probably both.
I would probably prefer the laser and the pen/knife machine to be separate, and for the price that seems like it would be reasonable to accommodate. However, this is a nice looking machine and the Hot Foil Pen is interesting.
I realize that op asked for a Linux solution. But for those on Windows, Adobe Illustrator with the $30 Silhouette plug in on a Silhouette 4 worked close to as well as the dedicated software and hardware I used professionally once everything was dialed in.