Within Channel - Tab, when adding Planner - allow 3rd option, link board via URL for users with access given in planner
If we created planner boards directly in planner and are not part of a specific team (with MS Teams), then we should be able to add the planner board as a URL. If the user has access, they will get into the board, if they don't they can request access.
At times, there are boards which are not open to everyone in the team. Currently, we did this via Website but it displays an entire planner page with left bar etc.