Google My Business currently does not allow businesses to schedule posts if they are considered a chain by Google's internal detection, as stated in its documentation - https://developers.google.com/my-business/content/posts-data.
In Statusbrew's Composer, Google My Business profiles with post feature disabled by Google (chained locations) are not available for selection. Review management in Statusbrew's Engage for chained Google My Business profiles will work seamlessly.
No third-party platform like ours will be able to schedule posts for chained Google My Business profiles.