I'm not Jeremy, but you should probably tag or PM him, so he gets an alert about this. I know he's generally pretty busy.
Thanks, SkyeFire! Busy I am, fortunately! 
Hi Mike!
Thanks for the great comment! Our team and I work hard on the content we release!
I answered your PM, BTW.
Ok, about the "Change my mind." Let's give it a go.
Let's get this out the way first.
I don't have any experience with Robotmaster.
I know some of their capabilities and features through research and demo, but nothing more than that.
We are indeed just a group of "industrial robot ppl" who had a problem "Simulating and generating robot programs for multiple brands without having to sell a kidney along the way."
So we made one...
("Made"... "Make" would make more sense as it's a never-ending process/project. One that we are pretty passionate about, to be honest.)
We created a tool to help you bridge the gap between your idea and a working robot by removing some of the programming pain points.
But it's still just a tool; it won't do everything for you. It's so flexible that we can cover a lot of use cases, but the user still needs to find the correct parameters for his project.
We do Stone Milling with other customers, using external axes.
Have you tried our software?
Inside RoboDK, you can recreate your station by importing the robot from our library, creating your external axes, etc. (explained with the videos you already know about).
You can then Sync the robot and the external axis together.
All of this should be pretty straightforward.
You mentioned using Mastercam.
RoboDK has a plugin for MasterCAM that lets you transfer your CAM program directly to RoboDK with just the click of a button.
So that's one step you won't have to bother about later.
Where things will get a bit more complicated is when you will have to optimize the path with the external axis.
It might go well for the first few parts, and you might find the right set of parameters in a few minutes, or you might spend a reasonable amount of time figuring out the right recipe for your setup.
Once you know about your system, generating new parts is very fast.
We do not offer on-site support/training, but we provide a call with the purchase of a license.
You can then purchase paid support bundle if you need our direct help. Otherwise, we provide support via email. (Exactly what I was doing before ending up here.)
I don't know what to say; try it out; if it's a tool for you, great.
It's the kind of tool that you might need to think around a bit to use the full potential of, but if you can do so, it's super powerful.
(Talking as Jeremy, not Jeremy from RoboDK. I work at RoboDK because I love the product, not the other way around. You can do so much with that thing for the price.)
Anyway, I hope it helps.
Robotmaster must be a good product; they've been out there for years, and a bunch of people are using it.
It won't be a wrong choice if you go down that road.
Have a great day.
Jeremy