We have been using a Twist workflow with InDeisgn for the past two years, and we are delighted. But we don't use OPI. Never have.

If you MUST use OPI, you need to work very closely with the vendor that is setting up your Twist workflow. It can be done, if you insist.

My advice is forget about OPI. It's really not an effective workflow, in my experience.

Regards,
Michele