My first post to any forum - ever - let' see how I do. I was having boot pain at fifth met/toe. Boot fit size, volume, and flex is perfect for me other than the one trouble spot. I base this observation from days on the snow. Searching online for reasons and solutions to the one trouble spot, came upon a lot of helpful info. By trial and error I discovered a problem with my knee/center of boot alignment. Solutions presented were cuff adjustment, canting, shimming under the binding.
Maxed out the cuff adjustment. It helped, but did not cure. So I tried something I had not seen in any discussion. I removed the boot liner, and installed a shim (2mm to 3mm thick) the length of the boot board on the medial side.
Results were better than hoped for. Boot still fits great, perhaps better than before. Pain is gone. Alignment by plumb bob center of knee mass (not knee cap) to seam of boot at toe is spot on. To my untrained eye I'm shifting from edge to edge left and right side with equal effort and no hesitation. Most important, I feel great on the snow.
Sounds like I'm patting myself on the back, but I'm not. I would very much appreciate opinions from people more qualified than me. I don't want to trade one problem for another, or worse, cause injury. Thanks for your help.