At this time, for your situation, there is no way to reduce or remove the 90-day security lockout you've received by disabling Cross-Save. While you're waiting out the time, please note that you can use the platform characters to play the content you've purchased. Once you've waited out the 90-day lockout, you can reenable Cross-Save and bring in the characters you actually wish to use if you still wish to use characters that are not native to the platform you're playing on.