I dont think mach4 loses them, more like when starting up it doesnt know where it is until homed.
Something you can try though is create a button and as a test put
local inst = mc.mcGetInstance()
mc.mcMotorSetHomePos(inst, 0, 175 * mc.mcProfileGetDouble(inst, 'Motor0','CountsPerUnit',0)) --X
jog x to 175 and shut down mach4 and restart, press button you should find your machine coords now at 175, however I cannot tell you how this will look on your system with say softlimits or offsets but worth atry.
DazTheGas