I tried it...I am guilty. I let the ITX bug bite!
I bought a 5700G, 32GB 3600MT/s memory, a Asus B550i Gaming Strix MB and a Goodisory A09 Black case with a Silverstone Flex 350W PSU.
I did this as a project for fun. (Not so much)
I had to take the case completely apart, I have small hands as well and when I got done...I swear I will never do it again!
I had long lusted after the Silverstone PT13 - a 1.3 liter Thin mini-ITX chassis. I wanted to use it for a passively-cooled micro-server, as sort of an upgrade to the way I had eventually started using my Raspberry Pi.
I found the seemingly right motherboard - a N97-based industrial board.
Mini-ITX SBC, N97, Alder Lake-N, 1 DDR5, 2 HDMI, 1 DP, 1 LVDS/eDP, 1 SATA, 1 M2M, 1 M2E, 1 M2B, 2.5 GbE, 8 USB, 6 COM, 1 GPIO, 1 PS/2
jetwayipc.com
Well, it was quite an ordeal. First, the motherboard's heatsink turned out to be absolute garbage. To their credit, the reseller sent me a passive heatsink for it and I attached a 92 mm case fan to the case's side grille, blowing directly onto it (although it covered only about 70% of the heatsink). Because the case wasn't designed for a fan, that meant I had to remove the front panel USB headers. The fan also intersected the front panel header for things like the power button, so I had to get creative, pulling the wires out of their connector blocks, shrink-tubing them, and then bending them out of the way.
Next, I did some airflow mods, to reduce recirculation and direct more of the air over the CPU heatsink. Those mostly involved blocking some of the vent holes by taping bits of black paper from the inside. Also, I folded a piece of plastic over part of the SODIMM slot, next to the CPU cooler, that deflected more air towards it. It formed a chute for some air to cool the SODIMM and exit out the side/top.
Finally, I tried putting another heatsink under the CPU, to draw away some heat and transfer it directly to the bottom of the case.
The final issue was the stand, which has holes in the bottom but sits flush with the table, blocking air from reaching them. So, I had to cut and glue little pieces of plastic so I could attach rubber feet, in order for there to be some vertical airflow.
This is the most case modding I've ever done. If I knew how much work it'd be from the outset, I probably wouldn't have tried. Looking back, I don't really regret it. Even though it's still noisier than I wanted, it's silent at idle and has worked very well for its intended purposes.