Finally got around to finishing my version of this - too many projects in parallel.
I downloaded the file from Thingiverse, but decided to just design my own. It is much easier to change the size of the holes in the design to fit the magnets rather than trying to find magnets that fit the holes. I ordered the magnets from Amazon, 30 for $12, 10x5mm.
The adapter that fits over the tool dust port is tapered and just a friction fit.
The two parts line up really well, not sure if I need to install a gasket between them, but I haven't actually done any serious amount of jointing/ planing to test it.
Here it is when converted over to planer mode:
To be honest, it is not that much better than what I had before. I used a 4" piece of thin wall S&D pipe, attached the hose to it with a clamp, and the pipe slid over the tool dust port with a friction fit. Cutting the piece of pipe took about 2 min. Creating the 3D model, printing it, ordering and installing the magnets - days
But this is much much cooler of course. Plus, it's good practice to design stuff, if you don't do it regularly you forget how the software works.