As the title states, I want to migrate to a new steam account. People have said to submit a support ticket but I couldn't find where to post one. Some said that you have to disable cross-save but I never enabled that (unless it's on by default).
Hey,
This is not possible, unfortunately.
Bungie does not support the transfer of save data between accounts. As you noted, the only option is cross-save which allows you to access data from one account on a different one as long as the feature is enabled.
As Swat pointed out, however, it is not possible to cross-save between two accounts on the same platform.