Well, implementing fillets and chamfers is no easy task, so it's well deserved to be there.

Source: been there, done that.

> Its not often you see 'fillets and chamfers' are tip-line features in the readme for CAD packages.

Well the readme states the following:

Solvespace on the other hand gets the workflow part right, but falls short by not importing STEP and the geometry kernel not supporting chamfers and fillets.

So I assume that's where that comes from.

Perhaps. I guess I'm saying 'oh boy fillets and chamfers' marks it as not very serious CAD hardware. That's table stakes

It has been one of the main complaints about openscad for some time

Hull and Minkowski operations sort of allow one to do this sort of thing, but add to the mathematical complexity in what is probably the worst-possible way....

fillets and chamfers are at the same time both ridiculously difficult and ridiculously important.

This is honestly the first thing I look for with anything new claiming "CAD".

Roughly every other week there is a new "The (programmable) CAD that fixes everything!" post on the front page, just for me to open them up excitedly and noticing that they use a mesh kernel and will thus never be able to provide fillets and chamfers painlessly (for the user). All while they are absolutely essential for a lot of designs, especially in 3D-printing, a well-placed fillet/chamfer can make the difference between an object that breaks upon looking at it funny and one that can bear significant load.

Yeah, it's a tough row to hoe --- I've been handling it quite differently in my own project, taking "Design for Manufacturing" to the ultimate conclusion and requiring that the part be designed by actually applying tooling:

https://github.com/WillAdams/gcodepreview

Needs a full-on re-write to make the G-code export (and import) work well, but lately I've been focused on exporting to DXFs w/ colour/layer tagging which was just added as an import feature in the CAD tool my side-gig employer does.

G2 fillets are the next frontier. Even Fusion doesn't seem to handle them well. I mean they can be created without much drama, but geometry derived from them is very likely to fail with no real reason.