That's actually how it works. Chamfers and fillets are handled by OpenCascade, so they can be applied to arbitrary edges. They only exist on the solid model though, so they are not integrated with the solver.

I'd be curious to see how native chamfers/fillets in solvespace would work, I imagine some amazing things could be done if they'd be part of the solver.

Source: I am one of the contributors.

If you think about it, it actually makes a tiny bit of sense. First, it is failsafe: Breaking the control line or shorting it to ground will not move the servo to 0%, shorting it to signal level will not move it to 100% - it just doesn't move at all and stops applying force. Any sentient being within the movement range will definitely prefer it that way instead of random movements. Second, it can actually be pretty precise: The driver circuit can be completely analog, it doesn't have to be limited by arbitrary digital quantization steps. All it needs to do is check if the current encoder value is above or below the target and apply power to the motor accordingly.

I'm a bit disappointed though that the original desktop version doesn't really play nicely on touchscreens.

For a printer, the devil is in the details though - quite literally: A printer needs to place tiny ink dots on the work piece in a fast, accurate, predictable, and repeatable manner. Placing just one single dot at a time would be prohibitively slow, so the print head needs an array of tiny nozzles in order to print multiple rows in one pass. The design also needs to ensure a consistent (and adjustable) dot size across all nozzles regardless of the ink level.

Designing and manufacturing such a print head is extremely complicated (if not impossible) for a hobbyist, and as of today there is no vendor-agnostic third-party design you can just buy off the shelf. The only forays into DIY printers are either rudimentary low-res single-nozzle designs [1], fully repurposing existing printer hardware [2], or reverse-engineering proprietary ink cartridges that come with a built-in print head [3].

[0] Technically, this is not entirely correct because a typical printer's Y axis is a rotating drum that transports the paper instead of a linear axis. Also, a printer's X axis is usually equipped with an encoder ribbon that allows for far more accurate positioning compared to the classic open-loop stepper motor systems used in many open-source designs.

[1] Example: https://hackaday.io/project/167446-diy-inkjet-printer

[2] Example: https://www.youtube.com/watch?v=_VP8ORq2al8

[3] Example: https://ytec3d.com/hp45-inkjet-printhead/

OTOH, I've already stopped posting and commenting and will only resume once they change their stance on moderation tools and third-party access. If old.reddit goes for good, I'll go as well.

This doesn't invalidate your point though - even if you're one order of magnitude off, your £200 solar panel will buy you about ten times its price worth of electricity.