Unfortunately, as a developer this would be impractical.
For example, this option would not work for projects that use JavaScript or use MSAL for authentication against Graph there are no permissions that can be applied to the same token to switch between these APIs.
If a user has a MIX of premium and basic plans you would need to use Graph API and get an MSAL token to CREATE or UPDATE a BASIC task. When the user suddenly switches on you to a PREMIUM plan you would need to prompt a different authentication context and switch to using SharePoint API's or DataVerse to CREATE or UPDATE tasks.
It would be even more difficult from a PowerAutomate flow. How do I know when to use one API versus another for creating tasks on a specific Plan? In even the JavaScript, C#, or any method there is only one way to identify you have a premium plan and that is to try to create a task on the Plan via Graph API and wait for it to fail.
I wish this would work but Microsoft needs to implement this functionality into Graph API. I have been telling my customers that rely very heavily on my solution to not upgrade to Planner Premium until this is addressed.