Please wise men share ye your wisdom (multiseat PC)h

So I made already two topic about that Sharing system resources near bare metal perfomance

and Proxmox vs Unraid for “2 gamers 1 CPU” setup

In short I want to make a “2 gamers 1 PC” computer for my two nephews to use and play simultaneously.

But reading further and further choosing proxmox or unraid or anything similar perplexes me

So I gave it a though and reading more about @CookiesAreAmazing suggestion of multiseat in linux I thought why not forgetting about resource draining “middlemen” such as proxmox and not just run linux as a main OS for my two nephews (with multiseat) and having seamlessly run the windows version of steam for them via KVM and something like SeamlessRDP ?

Wouldnt that be more efficient in terms of hardware resources needed and how those hardware resources are shared?

But the “seamless integration” part is what perplexes me could it be really as simple as double clicking steam and have it run under windows without clunky VM windows running in the foreground?

Also does it work in general or will I have to face a ton of buggs and BSODs?

What is your opinion?

I relist my hardware config again for convinience

CPU i9900k
RAM 2*16GB 3200 cl14
GPU1 Intel graphics
GPU2 Vega 64 nitro+
GPU3 Vega 64 nitro+
Storage mediums: 1TB nvme ssd divided into two partition (hopefully one for each windows client) , 1TB nvme for the linux client, 6TB WD blue for filesharing
MoBo Asrock Z370 taichi