Example from the creator of it https://youtu.be/WGsi5SCurpM

I watched his video and I wasn't totally convinced that it's better than tree supports. One example he showed used more filament and still left significant marks. Maybe the design can get some refinement once more people get their hands on it.

I looked forward to trying it out when I get a chance though, and hearing what other people think.

Agreed, no tool is perfect. However, I'm glad to have another tool in my kit!

Interesting. A screenshot of a random model

It has placed a supports correctly at the front of the view, but added an unnecessary support on the taper in the back. And is unwilling to place any support in the vertical slots. Still, it shows a good promise to be useful.

Scarring is mostly a matter of what you set your top z distance to vs support type chosen. Perhaps he left it too tight. And the amount of filament used by the supports can vary greatly from one model to the next. Tree supports often uses more material than you might think for example.

Supports are not a one size fits all.

Supports are not a one size fits all.

Exactly.

This isn't the perfect tool for every model, but there are definitely situations where a support fin would be perfect, and they're hard to get with most (all) slicers?

I have been adding those fins supports in CAD as I need and want them. This can automate the operation to a certain extent.

Support fins when added during design phase are insanely good, additionally you can use support "wedges" for internal geometry, huge bonus is ease of removal (don't really care about visual aspects).