My ankles have always been weak and I have quite flat arches where my feet roll in. This means I am skating on an inside edge more than I should. I have bought expensive rigid arch support orthotics but this hasn’t made my feet (especially right foot) any straighter. I have Graf Bolero boots which are new and quite comfortable and good to skate in. Previously I had Edea Chorus which were far to stiff in the ankle and were incredibly painful to wear, as well as being way above my level of skating (competent beginner).
The Graf Bolero has a riveted blade so moving them isn’t an option. Is there anything else I can do?
You'll need to buy a boot and a blade attached with screws (either a pre-packaged kit or separate boots and blades). To correct for pronation, you have three options (separately or in combination): (a) corrective footbeds or orthotics inside the boots, (b) move the blades towards the inside of the boot, and (c) shim the blades to raise the outside edge. Since you've tried (a), and it hasn't worked, you'll need to try (b) or (c). I pronate strongly, and I need all three options together.
[Technically, it is possible to remove rivets, insert shims, and reinsert rivets. More commonly done with some models of hockey skates. But likely not cost effective for low-end figure skate kits. You're better off buying new boots and blades.]