Another two part suggestion.
1) Create the option to control the crease in two modes. One as a solid fillet and another as a solid chamfer.
2) Expand on this to be able to create inbetween states between fillets and chamfers and more.
See 7:!5 in this video (this is a video I included showing how t-spline booleans should work, from another idea station post)
https://player.vimeo.com/video/85143354