tested this approach and not recommended
Hi, i was able test this approach, by having a 140mm fan from deepcool (600-1500 rpm i guess, high cfm). When i use the wraith spire fan on the cpu cooler (removed the shroud and dust filter), the temperatures are quite well (mid 60's in prime95). But when i put on the 140mm fan, i have to shift it a bit s the fan blades wouldn't touch the case cover, due to bending from the off-standing area for the cooling area. As i shifted the fan, the cpu cooler won't get much fresh air in the opposite corner of where i shifted the fan to, resulting in 70-80 degrees when testing, it would probably have hit the 90's but i just didn't want to go that far. What i also have tested is using a 140mm fan with 120mm mounting holes in the gpu area, with success: My RX570 4GB only gets to 70 degrees, AND i was also able to mount another 140 fan next to the first one (actually not fitted by screws as it's offset) but its being held by all the cables in there and the other fan, and its really tight, the only thing i feared was that the fan could interfere with the gpu fans, so i tried to move one of the power cables for the gpu in a way that the gpu stands away from the case fans (obviously i would have to use some other kind of spacing material, like a wooden piece or whatever) but until now it's absolutely fine, GPU temps when on load: 65-67 degrees!