So you want to know how to prevent/delay Microsoft from installing /changing graphics drivers automatically...is that your question? And Microsoft's response to you wasn't sufficient?
Since you have a legacy graphics card (means no more updates) it's hard to imagine Microsoft installing any other drivers...you have choices of two > Legacy
How to install them > Clean Install AMD Graphics Drivers
Kind of solved my problem... Made a clean install of the driver. Now some driver is installed that doesn't work and only the Intel HD works... But this solution prevents Windows from installing the "broken" driver again.