Reading the posts in the "Bug Reports" in this forum, I came upon a topic started by Wolf called "Standalone Game Bug : Level Loading".
In that topic they discussed keeping track of v-ram usage when loading and testing a game. Because that topic is closed, I decided to post here.
I use a combination of HWiNFO and Rainmeter with the Gadgets skin. The Rainmeter skins can be forced to always stay on "Top", allowing them to be visible in game (Stay Topmost). Not just in GameGuru, but in many other games and programs. Rainmeter skins have many other functions besides monitoring hardware. You could keep track of the weather, e-mail, a remote server, etc. They can even be moved around on the screen when you go to the settings in the test game ( double tab )



HWiNFO

https://www.hwinfo.com/


Rainmeter

https://www.rainmeter.net/


Gadgets

https://silverazide.deviantart.com/art/Gadgets-3-0-1-522574269


Edit:

While changing the values in HWiNFO.inc to get the fan speed of the GPU to show, I found the following note:

NOTE: As of this writing, AMD video cards do not report the percentage of RAM used by the GPU,
nor the amount of RAM in use. Because of this, the GPU Meter cannot calculate the total RAM available on your card nor the amount free.
Use the Direct3D values instead to allow the gadget to report Direct3D memory usage, which is not the same as reporting RAM usage.