What you're terming "blocked" may not have anything to do with a BIOS setting at all.  It may simply be a design compromise brought about by the price point at which this system was designed to sell. This is a budget system designed for a budget price point.  It was never intended to run intensive gaming - or demanding apps from Adobe. The budget you have determines the features you get.
Hi, a few months ago I bought an Inspiron 5575, it comes with radeon vega and 256mb of vram. Today I have updated memory to 32gb and I found Im not able to increase the VRAM? New Adobe Suite requires a minimum of 512 VRAM, so I'm not able to use it in a pretty new laptop? Really disappointed about this, is there any plans to update BIOS and able us to increase VRAM?
Inspiron 5575 blocked VRAM size, really?