Sorry, just one more thermald debug log to attach, as I was able to reproduce the issue with the read-only sysfs attributes.  After stopping thermald in debug mode at the previous session, I was unable to change pscale's max_perf_pct or any/all of my CPU's scaling_max_freq past a certain point. 

root@ossy:~# echo 100 | tee /sys/devices/system/cpu/intel_pstate/max_perf_pct
100
root@ossy:~# grep . /sys/devices/system/cpu/intel_pstate/*
/sys/devices/system/cpu/intel_pstate/max_perf_pct:50
/sys/devices/system/cpu/intel_pstate/min_perf_pct:50
/sys/devices/system/cpu/intel_pstate/no_turbo:0
/sys/devices/system/cpu/intel_pstate/num_pstates:22
/sys/devices/system/cpu/intel_pstate/turbo_pct:19

root@ossy:~# for i in /sys/devices/system/cpu/cpu[0-3]/cpufreq/; do 
> cat $i/cpuinfo_max_freq > $i/scaling_max_freq 
> done

root@ossy:~# for i in /sys/devices/system/cpu/cpu[0-3]/cpufreq/; do grep . $i/*; done

/sys/devices/system/cpu/cpu0/cpufreq//affected_cpus:0
/sys/devices/system/cpu/cpu0/cpufreq//cpuinfo_cur_freq:1799853
/sys/devices/system/cpu/cpu0/cpufreq//cpuinfo_max_freq:3700000
/sys/devices/system/cpu/cpu0/cpufreq//cpuinfo_min_freq:1600000
/sys/devices/system/cpu/cpu0/cpufreq//cpuinfo_transition_latency:4294967295
/sys/devices/system/cpu/cpu0/cpufreq//related_cpus:0
/sys/devices/system/cpu/cpu0/cpufreq//scaling_available_governors:performance powersave
/sys/devices/system/cpu/cpu0/cpufreq//scaling_cur_freq:1799853
/sys/devices/system/cpu/cpu0/cpufreq//scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu0/cpufreq//scaling_governor:performance
/sys/devices/system/cpu/cpu0/cpufreq//scaling_max_freq:1850000
/sys/devices/system/cpu/cpu0/cpufreq//scaling_min_freq:1850000
/sys/devices/system/cpu/cpu0/cpufreq//scaling_setspeed:<unsupported>
/sys/devices/system/cpu/cpu1/cpufreq//affected_cpus:1
/sys/devices/system/cpu/cpu1/cpufreq//cpuinfo_cur_freq:1799853
/sys/devices/system/cpu/cpu1/cpufreq//cpuinfo_max_freq:3700000
/sys/devices/system/cpu/cpu1/cpufreq//cpuinfo_min_freq:1600000
/sys/devices/system/cpu/cpu1/cpufreq//cpuinfo_transition_latency:4294967295
/sys/devices/system/cpu/cpu1/cpufreq//related_cpus:1
/sys/devices/system/cpu/cpu1/cpufreq//scaling_available_governors:performance powersave
/sys/devices/system/cpu/cpu1/cpufreq//scaling_cur_freq:1799853
/sys/devices/system/cpu/cpu1/cpufreq//scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu1/cpufreq//scaling_governor:performance
/sys/devices/system/cpu/cpu1/cpufreq//scaling_max_freq:1850000
/sys/devices/system/cpu/cpu1/cpufreq//scaling_min_freq:1850000
/sys/devices/system/cpu/cpu1/cpufreq//scaling_setspeed:<unsupported>
/sys/devices/system/cpu/cpu2/cpufreq//affected_cpus:2
/sys/devices/system/cpu/cpu2/cpufreq//cpuinfo_cur_freq:1799853
/sys/devices/system/cpu/cpu2/cpufreq//cpuinfo_max_freq:3700000
/sys/devices/system/cpu/cpu2/cpufreq//cpuinfo_min_freq:1600000
/sys/devices/system/cpu/cpu2/cpufreq//cpuinfo_transition_latency:4294967295
/sys/devices/system/cpu/cpu2/cpufreq//related_cpus:2
/sys/devices/system/cpu/cpu2/cpufreq//scaling_available_governors:performance powersave
/sys/devices/system/cpu/cpu2/cpufreq//scaling_cur_freq:1799853
/sys/devices/system/cpu/cpu2/cpufreq//scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu2/cpufreq//scaling_governor:performance
/sys/devices/system/cpu/cpu2/cpufreq//scaling_max_freq:1850000
/sys/devices/system/cpu/cpu2/cpufreq//scaling_min_freq:1850000
/sys/devices/system/cpu/cpu2/cpufreq//scaling_setspeed:<unsupported>
/sys/devices/system/cpu/cpu3/cpufreq//affected_cpus:3
/sys/devices/system/cpu/cpu3/cpufreq//cpuinfo_cur_freq:1799853
/sys/devices/system/cpu/cpu3/cpufreq//cpuinfo_max_freq:3700000
/sys/devices/system/cpu/cpu3/cpufreq//cpuinfo_min_freq:1600000
/sys/devices/system/cpu/cpu3/cpufreq//cpuinfo_transition_latency:4294967295
/sys/devices/system/cpu/cpu3/cpufreq//related_cpus:3
/sys/devices/system/cpu/cpu3/cpufreq//scaling_available_governors:performance powersave
/sys/devices/system/cpu/cpu3/cpufreq//scaling_cur_freq:1799853
/sys/devices/system/cpu/cpu3/cpufreq//scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu3/cpufreq//scaling_governor:performance
/sys/devices/system/cpu/cpu3/cpufreq//scaling_max_freq:1850000
/sys/devices/system/cpu/cpu3/cpufreq//scaling_min_freq:1850000
/sys/devices/system/cpu/cpu3/cpufreq//scaling_setspeed:<unsupported>


But when I restarted thermald (in debug mode again, attaching log), it now correctly saw that my CPU was cool and turned up my performance all the way again.
pstate-frequency version 3.7.2
    pstate::CPU_DRIVER   -> intel_pstate
    pstate::CPU_GOVERNOR -> performance
    pstate::TURBO        -> 0 [ON]
    pstate::CPU_MIN      -> 50% [1850000KHz]
    pstate::CPU_MAX      -> 100% [3700000KHz]

So I guess it's just rather fussy. If it was properly putting my performance back to max then I wouldn't really have too much cause to complain but as it is it can restrict me until it's restarted.