Hello,
Welcome to Microsoft Community and appreciate your time taken for sharing detailed information. I understand that Two different gmail accounts with one subscription to Microsoft365. I could share with you some of my thoughts on this issue.
I would like to ask if you subscribe to Microsoft 365 through Google or directly subscribe to Microsoft 365 directly at Microsoft. If it is Microsoft 365 with an official Microsoft subscription, the two accounts cannot share the same subscription. But if you subscribe to Microsoft 365 Home Edition, you could share your Microsoft 365 to another Gmail account, and Microsoft 365 Personal Edition can't do that.
Feel free to post back if you have any additional questions.
Best Regard,
Kevin | Microsoft Community Support Specialist
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