I've localized this issue's origin to be somewhere in the bluetooth handling -
Sending data to HC-05 every 100ms, looping the app side BT receive every 10ms.
test scenario put in place that also when printed, 0.1 is added to value in C++ code.
what I see is that the input display will rapidly go from say 0.1 to 0.6 very quickly (I see .1,.2,.3.4,.5 on screen), then pause for maybe a half second, then go from .6 to 1.1 - oddly half second intervals, although not perfect.
clearly on the app side since the app is getting each data bit - app also slows down only during bluetooth reading, data logging chugs hard (it reads whats in the input boxes every 100ms). when the "set variable to receivetext BT -1" is removed, speed returns to normal.
id think 10 times a second wouldnt be that big of a deal - im either doing something wrong (string structure is such that it takes a long time to read), or the HC-05 just takes a long time to be read from (which I doubt).
any help would be greatly appreciated.