How far into the forefoot does the foam go? This is a problem area for me with a size 13 street shoe and a 100mm wide foot. Even sized down to a 28.5 boot the Ultra is a 102 mm last. Can the foam take up 2-3mm of space effectively in that area?
@Springer, I am responding because I have a similar foot, maybe a little narrower, as you and recently bought two new ski boots. Not because I am an expert on the subject like ONK is.
From other sources, I have learned that you want to typically be within 1-3mm of the last width, or slightly less. This would be a normal "good" fit. So the professional foam liner should easily take up 3mm of space. ONK can confirm, but I think the answer is yes. More importantly, the 102mm last width is a single point to point measurement and only to be used as a guide. Its about the entire last shape and 3D fit of the foot pocket in the boot. Even if loose at the one point, if tight everywhere else you maybe good. You can make a footbed thinner or thicker to move you up or down in the boot and the last width measurement will change. My size 13 foot measures somewhere between 95-100 mm wide (depends on how the measurement is taken) and I am in a 29, 102mm last Atomic 130 Club Sport boot which is the snuggest and best fit I have ever had (skied Lange boots all my life). I also tried a 28, 96 mm last Atomic Redster World Cup boot and the width was OK as well, but too short. The liner in the WC boot was thinner, and the boot was stiffer, which is why I choose to go with the Club Sport. If I chose a 29 size WC (98mm last) I don't think it would have been as comfortable a fit and too stiff for off piste skiing. (it is a race boot) So my point is I am in a 6mm wider last, but with a much thicker and more comfortable liner, and the fit is very snug everywhere except the toes, where the boot is just right, roomy but not too loose. Starting the buying process, I assumed the 102mm last would be too wide, but I was dead wrong about that. Just for a final comparison, my old boot is a RS140 Lange, which in size 26 has a 97mm last compared to the Club Sport 96 mm last in a 26. The Club Sport is a much snugger fit even though only 1mm last size difference. It required a punch at the ankle end of my 5th meta, where as the Lange did not. It is a noticeably narrower boot than the Lange and is made so it can be "modified" as needed for comfort with high precision. I will ski it for the first time on Wednesday, but I can tell already it will be a higher performance boot for me.