GPU upgrading on All in One PC and BIOS - how it works?

[DigitalGhast]

Hi.

I have some questions, that I either couldn't find answer online or the ones I got, were straight up confusing.

I own an All in One HP Z1 G3 desktop. It's an old PC, but it was always super reliable for me and suits me very well. Unfortunately the GPU is a trash.
It has Quadro M1000M which these days lacks basic features like eg. DirectX 12. 

I was hoping to upgrade it, to give it last fresh breath. I found the GPU Arc A370M that on paper should work fine. The connection type, TDP, dimensions are all ok according to the Service and Maintenance Guide.

But I stumbled upon posts on the internet saying, that you cannot just put in the GPU that the PC was not shipped with, cause it won't be recognized by the motherboard. I dug a bit and there were conflicting posts, that HP does not disable other GPUs, some of said about BIOS whitelisting (which I heard about WiFi cards, but never about the GPUs) and the questions I asked about it on HP Forum were unanswered.

So how does it work? Is GPU whitelisting a thing? Or something else can prevent me to make this GPU work on my PC. Is it even worth a hassle? The GPU costs 200 USD, so it not super expensive, but also way to expensive to have it not working.

I would really like to hear from people who are more knowledgeable about it, cause at his point this is just too much from me.
Thanks!