A 72mhz ARMv6 from STmicro
Why do you keep bringing up ARMv6? ARMv6 is a CPU architecture and uses complex caches, TLB units and a virtual MMU. I don't know of anyone trying to use these for flight controllers. The Cortex-M architecture, which is the basis for all of the common ARM based flight controllers (OpenFlight, BrainFPV, Naze, etc.), is not ARMv6. I don't think you understand what you're talking about.
Floating point isn't actually a good thing in flight controllers, fixed point is preferred..
PID controllers using floating point are available now in Cleanflight. Read about them here. Other code bases, such as BrainFPV and OpenFlight use the floating point units as well. Fixed point is preferred only by fanbois using MCUs without floating point units.
Super scalers make execution timing unpredictable
No, they don't. Out-of-order pipelines and elaborate branch predictors do that. Cortex MCU pipeline is in-order and the branch predictor is designed by ARM to be conservative and not cause lengthy pipeline stalls so the Cortex line remains suitable for real-time MCU applications. The timing characteristics of every instruction in every mode of Cortex devices is well known. This `problem' of unpredictable timing with ARM MCUs is a fiction inside your head.