I think you are doing just fine. Reading that article initially scared the crap out of me because it sounded just like the company I work for (a 1-3 nice machines, an idea, and an engineer). But then I kept reading and it sounded like every company like that made false promises. Something that is just not acceptable. You are very realistic about things and don’t accept orders if stuff isn’t in stock or wont be in for a while.
Honestly, as long as the website stays running I think the machine will continue to evolve with or without you. The shop may go away, but there are so many services where you can get 3d printed parts. Now many public libraries even have a few printers for people to use (though usually at way over material cost). All of the other materials are easy enough to find, and the firmware is publicly available. That is another key reason that other companies fail. Your design is totally open and there are CAD files available online (though stls are hard to work with).
This is a kind of relating example:
The robotics team that I am on just finished up with a contracted project for one of our sponsors. In the end the customer suggested a few basic changes due to things they failed to communicate to us in the initial stages, but they loved it none the less and are planning on having many more professionally made. We gave them the cad files and they are just having the parts printed on nice machines because the number of parts they need does not justify the costs of having molds made for injection molding.