1.Download the jpeg. file
2.Check the model name of your motherboard
3.Download the image from the motherboard website
ex. ASUS STRIX Z270I GAMING



4.Put your motherboard image on our drawing

5.Example of how to calculate the length
ex: CPU 4+4 Pin, Check the drawing is listed below: CPU 4+4 is around 240mm, so you will need around 250mm cable length.
But, we will suggest you to reserve at least 50mm length buffer to avoid any issues

Have you guys thought about revising the case slightly taller to fit a slim 240mm rad for custom loop? It could also be done by moving the motherboard closer to the top or bottom without adding too much height.
Cheers it is a wonderful case.
Actually, we were developing this kind of the pc case that you mentioned. However, we don’t not have further news for this case at this moment.