REJOICE!!!! You can finally schedule and mange your connected Instagram accounts from the new and updated Facebook Creator Studio.
Any Instagram account that is connected a facebook account / page can access this, allowing you to schedule post to your feed and IGTV.
It looks like you may also be able to schedule story posts in the near future with this feature opening doors for so many social media managers and businesses.
Over the last 6 months Instagram has slowly allowed various third party apps like buffer and hoot suite to start posting scheduled posts to Instagram but with Facebook now allowing the feature too it could hit these big scheduling apps.
We look forward to further features and adding the scheduling of Instagram stories.