help about PCB [hlp]
As you know, keep the enough temperature of the pad for you hand soldering is important and in effect.
The heat will transmit from the GND pad to the connected GND copper while you doing the componet pin solder on board use solder iron, could we slow the speed of the heat transmition? yes, that's why we design the mode of connect the GND pad to GND copper in thermal tie. in you case, because you use mutil-layer stack, and each layer must have had thermal tie to connect the pad with copper, so the speed of heat transmition is more fast than ordinary board use 2 layer stack. decrease the number of thermal tie or isolate these pad from gnd copper connect is very easy to do.
last way that I made mention of previous post would result you to take more time to measure the pad temperature change. I did it use the thermocouple, then I had got the best width of thermal tie for hand soldering on my board, but it took mine three months time. I don't think that you will do it in this way.
So far more about my project all on above