Inner (90˚) edge is easy – I can just apply a bevel modifier and limit by angle. I'm having trouble with the outer edge. The bevel modifier either does nothing or makes a mess because the faces near that edge are too small. I've messed around for a few hours and have tried using the sculpting tools, but they don't work well because of only having two faces on the top. I tried selecting all the vertices near the edge and scaling them in towards the center, but it doesn't look good and will take a really long time to get a good result. I also tried doing some boolean stuff with a torus to cut off the sharp edge, but I couldn't get it to look right.
I found this post that addresses almost the exact same problem, but the solution given would ruin the soccer ball look of the model and seems to only be a visual solution. I plan on 3D printing this (soccer ball napkin rings), so the model itself actually needs rounded edges. How can I do this?
I created this model by loosely following this tutorial then using two boolean modifiers with a cylinder and a rectangular prism. Do I need to somehow model this in a different way to be able to round the edges?