don’t go 150mm for the fox, a set of 32 140 rlc’s with a tapered steerer (and 15mm qr) will be absolutely fine… alternatively, a set of revelations would also work well.
the asr5 has the capability to be quite light, so there is no point in weighing it down with 2kg+ forks.
i ride with rlc 120’s and tbh, they handle everything perfectly… i can do the final descent of the skyline @ afan flat out without getting out of depth… if you go to 140mm, it will of course be better, but the climbing abilities will be compromised a little.
of course, if you are not interested in the climbing abilities, perhaps the 575 or sb66 would be better choices for you?