Did you try to optimize the code to speed things up during mining? I suspect it goes kind of "out of sync" at times
The ethproxy protocol need the full hash sent to the pool, this is calculated with the CPU. I see that other miningsoftware have moved the cpu verification and submit code to it's own thread. This might help abit. TBMiner is not working good on low difficulty pools because of this.
Understood. The higher the difficulty the best TBM can do, from my experience Hiveon is one of the pools with the lowest difficulty. You're in the right direction to 100% solve the issue but you have to rewrite the code for this pool and run a special kernel when hiveon is detected.
Xintensity is 71 by default for this pool, I suppose is by design but does not look that fast from my tests, share ratio is still higher with lolminer