I haven't been able to get the internal qca8511 switch to work, which both the PHYs are hooked into. I was able to make one of them work when using a modified second stage uboot that brings up the switch but that was it. ipq806x-dwmac also needs QSGMII support added though this was easy enough as all the info is available in qsdk.
Apart from this the device is the same as the MR52. I even installed the image on the MR53. Unfortunately I really don't have the time right now to make more progress.