I have a Redmibook 16.1 with ryzen 7 and 16gb ram with bios version 0909.

The bios is fully locked, I cannot change the ram speeds or allocate more memory to the integrated vega 8, it has 512mb right now which is not enough.
My other issue is when I plug it in it slows down considerably, as others also mentioned on the chinese forum.

I found the drivers but you cannot even load the page or see the newer laptops without using a chinese vpn.
Here the link for all the laptops: https://www.mi.com/service/bijiben/drivers/?display=showall
Here is the link for this laptop: https://www.mi.com/service/bijiben/drivers/A21

If you don't want to pay for vpn just for a few minutes to download some drivers, just use your phone and download Transocks Free VPN for Chinese, that way you can go there for free.