The problem I think with a 140mm rad in the bottom is I don't think you will be able to fit a 140mm fan on top of a 140mm rad. You can do this with the 120mm rad/fan because the adapter offsets it towards the front of the case, avoiding the spine and the PCIe bracket. But while you have ~28mm of clearance under there for a fan, you don't have 27mm+15mm of clearance for a 140mm square object. So you could do a 140mm rad, put an adapter on top, and then put a 120mm fan on top, but I don't think 140+140 are supported.For custom loop, yes (27mm rad plus 15mm fan are officially supported). AIO are not officially recommend in the bottom
And again, this is only for custom loops/rads and not AIOs because of tubes, unless you are using the 92mm AIO from Asetek.