Max resolution is based on the Interface.

VGA DVI HDMI old school has limits.

Single or Dual Link also matters

DVI TO HDMI is limited to 1920 X 1080

DUAL LINK DVI is limited to 2048 X 1536

DVI-I and DVI-A is analog vga.

This has zero to do with which GPU you have and everything to do with max output of the connector.  Thats why 4k requires display port 1.4 or HDMI 2.0  and 5K requires DUAL DISPLAY PORT cables."5K" is ambiguous, since sometimes it's used to refer to 5120x1440 and other times it's used to refer to 5120x2880.

To display 5120 x 2880 at 60 Hz and 30 Hz, both DP1 and DP2 must be connected.

https://downloads.dell.com/manuals/all-products/esuprt_display_projector/esuprt_display/dell-up2715k-monitor_user%27s%20guide_en-us.pdf

5K REQUIRES DISPLAY PORT

Both the adapters below are passive and Bi directional.

Thats also why DVI to HDMI says 1080P max

https://www.amazon.com/Rankie-Adapter-2-Pack-Gold-Plated-Converter/dp/B00ZMVGTA2/

SAME with DVI-I to VGA

https://www.amazon.com/DVI-I-Adapter-Benfei-Female-Plated/dp/B07G77CBBB/

Newer cards remove DVI-I and DVI-A so they are DIGITAL only.

AKA GT1030 1050 1060 1080 does not have ANY vga connectors.

https://www.amazon.com/Rankie-HDMI-Adapter-3-5mm-Audio/dp/B00ZMV7RL2

Display PORT TO VGA or HDMI TO VGA is one way only.

MAX IS HD

Not until HDMI 2.0 will you be able to do 4K over HDMI at 60fps.

DVI -A is VGA DVI-D CONVERTS TO HDMI WITHOUT SOUND

Display port 1.4 or HDMI 2.0 are REQUIRED for 4k

If your card does not have that you NEVER GET 4k EVER.

"max resolution of 4096×2304 does this mean the total of all monitors cant exceed this figure or can you run multiple monitors at this resolution"

I doubt you are willing to pay for the hardware that supports what you want.  The monitors by themselves are $500 or more. However maybe money isn't a problem for you.

this too has little to do with GPU and more to do with the amount of dedicated ram for the GPU the amount of display port outputs and what you are displaying aka static pictures or moving images.  LAPTOPS do not typically have Multiple Display port outputs.  Laptop with Thunderbolt3 can support EXTERNAL GPU that supports multiple 4k or 5K displays.

https://www.gigabyte.com/Graphics-Card/GV-N3090IXEB-24GD#kf

https://www.dell.com/en-us/work/shop/nvidia-quadro-p2200-graphics-card-quadro-p2200-5-gb/apd/aa714805/graphic-video-cards

• Chipset: NVIDIA Quadro P2200
• Video Memory: 5GB GDDR5
• Memory interface: 160 Bit
• Max. Resolution: 5120 x 2880, support 4x Display monitors
• Connectors: 4x Display Ports. Support up to four 5120 x 1440 monitors at 60Hz, or dual 8K displays per card.

qHD, and QHD, while spelled pretty much the same couldn’t be any more different. qHD stands for a quarter of full HD, i.e., four times less than 1080p. The typical qHD resolution is 960 x 540 pixels or 540p. QHD, on the other hand, is four times the standard HD resolution. Keep in mind, four times the HD resolution, not Full HD. The typical QHD resolution is 2,560 x 1,440 pixels or 1440p. That’s four times as many pixels as 1280 x 720 or 720p.WQHD is referred to as 2K. 5K describes a display resolution of 5120 x 2880 2DP cables  OR  5120 x 1440  1 DP cable.

5120 x 1440 resolution is not possible with Intel® Graphics driver versions

Environment:

• Windows® 10
• Samsung* CRG9 Monitor or similar that supports resolution 5120 x 1440 via display port
  

How to fix it:

The issue has been fixed with driver version 26.20.100.7985 or higher.

• 5k is 2 different things

DISPLAY PORT REQUIRED

https://www.intel.com/content/www/us/en/support/articles/000025675/graphics.html
hope this help answer OP question.

The link says for Intel 6th and 7th gen integrated gpu, you can display 4096x2304 @ 60 Hz on each of the three monitors connected via DP.  max 4k resolution is supported on all three monitors.

“Graphics controllers support up to three streaming independent and simultaneous display”

I think by independent it means the three monitor displays are not cloned.