[GUIDE] Quiet fan replacement for AORUS Gaming Box GTX 1080/1070
As far as I'm concerned, i think the idea behind this is to make sure the hot air doesn't escape into the enclosure. Usually it's a better choice to go with positive pressure, but i think in this case, it's actually better to make sure the thermal energy is disposed of properly and thereby the pull design. This is just speculation, but i highly recommend not changing the flow direction.
Having taken it apart to get the case fans connected back then, i remember that the PSU has a plastic sort of inner casing, possibly to avoid shorts, and - as far as i remember - this plastic also blocks many of the air vents you can see around the PSU. The only open one is the big one facing the side of the eGPU enclosure to pull air in, which leads me to believe they already put the plastic there so the PSU doesn't suck in warm air from the graphics card instead of the - supposedly - cooler outside. It's also possible the PSU design is made so the parts that need the most cooling are placed just so that the pull design prefers to cool those, while with pushing air in, and especially turning the flow direction around, could result in those vital components getting less cooling. Keep in mind, this is all my assumption and potential theory, it may even result in better cooling. In the end, you can only give it a try and hope it works out, for me, I didn't see any profit in changing the design so far, it all worked and still works well with the modifications i made, even after 10 months.
@ishikawa_goemon if you're still looking to reduce the GPU temperatures, I can highly recommend looking into undervolting the GPU! On my GTX 1070 undervolting resulted in a reduced power draw of almost 40 % while still maintaining the same performance. Since it's electronics we're talking about, almost 100% of electrical energy are converted into thermal energy, which means that the reduction of power draw on the gpu/card results in significantly lower gpu and enclosure temperatures (and possibly reduced component wear as well)