I use a lot of open source software tools at work. I would not like to pay for them. But more helpful is that they have huge volumes of users and some fraction are dedicated enough to give back into those projects. They are (IMO) superior to the proprietary tools. They actually work better for me, and when they don’t, I can easily give them a pass because of the price, or try some version that someone has tried to fix.
I have made a few hobby software projects and I have open sourced all of them. I do that because I get so much from FOSS to make my living.
As a nice side effect, I have had some nice people contribute and a few users have donated some money. Not enough to put food on my table, but enough to pay for some of the tools.
I do not make my living on open source software. I make my money working for a company that makes proprietary code and charges a lot for it. I am a long way from having enough demand in my hobbies to support me and my family. I believe it would be orders of magnitude harder to do that with hardware (vs software).
I would love to live a life where I could pay for everything I need with projects I love. As the icing on the cake, it would be amazing to be able to allow that project to be open source. I just don’t have that luxury.
You have most of that dream. You have made a project you love and it has been prosperous back. On top of that, this thing isn’t open source, but it is altruistic. It does have community.
It is possible for someone (from almost anywhere in the world) to participate. Someone can use your design, follow your instructions, load it with preconfigured firmware, and make it work for them, even build a business from it. It has happened thousands of times.
Your model, of making a business that supports a community and a community that supports a business is great. I don’t think there is a real legal tool to enforce that in a perfect way. I honestly don’t know if your current license even comes close.
From only your (bottom line) perspective, the only way changing the license makes sense is if the project becomes more popular (or measurably better) enough to overcome the losses from other stores (especially international ones) and the extra cost of supporting new users. I don’t believe it will stop the trolls at all.
If it was possible to do that. To have more customers, who appreciate it more, and support you more. Then it would be quite a boon. The “nontangable” benefits to you would be great.
If it only allows other companies to profit. And adds new support burden, then it wouldn’t be worth it for you.
For the rest of us. You bring in a huge benefit. For one thing, there is a reliable supplier for everything we need (except raspberry pi ). You bring us valuable updates to the design. You fill in the gaps when no one else wants to. You captain the ship, making hard decisions and sticking to them (when we have to). What helps you do those things helps us.
There are some ways a more open license could help us. For one thing, there might be a supplier that would add value or bring the prices down. There may be derived designs with improvements. There may be many more users, which would bring in many more awesome projects and mods. Edits could be merged into new versions if they make improvements. The project could live on far longer than any of us if it has this perpetual open support.
That is the most honest evaluation I can give. Provided all of that, I think the current license, and enforcing it with trademarks is a known winning solution.
If you wanted to go farther, you could. You could even still enforce the trademark (Mozilla Firefox is open source, but derivative projects (iceweasel) have to change the name. So is Google chrome (chromium)). It would be a risk of losing business and it would potentially give you a lot more business. Or it may do nothing. The outcome is unknown. There is an actual risk. But I don’t know how to predict the outcome. My guess is the most likely outcome is that nothing still really change. The second most likely is that you will lose some international business, and mods will be a little easier to do.
I will back you no matter which way you go.