nice update but a 5 Ghz Interface is still missing why?
I've debated about this for a while, and originally avoided MikroTik 60 GHz because of it for 6+ months.
Adding 5 GHz failover to 60 GHz just "increases" the range of the 60 GHz hardware. The problem is - if you didn't have the 5 GHz spectrum available in the first place, then you will be operating at limited speeds during failover. As a result, you aren't actually increasing the effective range of the hardware, you are using it in a circumstance where it can't meet bandwidth requirements and uptime requirements. And, if you have the 5 GHz spectrum at the longer ranges, it probably makes sense to just use 5 GHz instead of a mix.
I think it makes more sense to use 60 GHz within the tested limitations instead of using 5 GHz failover to try to buy more range. If you need more range, it is probably more reliable to add hops or switch to a band that already supports it.
[All that said, I think most microPoPs can be supported with 60 GHz for LOS and 5 GHz for short NLOS links. I would not be opposed to an AP that did both and could have mixed clients or have clients that could do either.]