Thanks doyal, doggies & lion. The boots are for my daughter. The problem is on/off, not pressure. The high arch is well handled with a custom footbed. But she can't get a lot of boots on with herhigh instep, and those she can get into are very painful to take off. We'll definitely get professional fitting, Your replies are very helpful in giving us some ideas where to start looking.
I've got a pretty high instep/arch and I have Nordica SM's, they are a superb fit, I can't imagine ever skiing in another brand.
When I last bought boots last year, I found some that I tried on had very 'slippery' liner material, it definitely helped getting them on, but some of them were so extremely slick I felt like my foot was going to slip right out again, even buckled up. If it's an on/off issue, this sort of liner material might help.