As far as I see, it's a standard OP structure. Current gain isn't a parameter here, I think. You have voltage gain, output impedance, current limit. Which parameter you want to modify?
the parameter which to modify is Direct Current (DC) gain or voltage gain. How to improve the parameter? which stage in OP that we need to modfy? thanks..
question 1: the problem is : how to raise 30 % direct current (DC) gain in op-amp circuit ?
answer : try to change the resistor R4 value to 1K , Q10 multiplier to 15 times and change the Q8 value to 0.2
Question2 : Do we need to do something at R9 & R10 to improve it?
or depend on the Vcc? answer : no...
Optimization of the component parameters can be used only if all other reserves for the structural and circuits topology improvement are exhausted,which in practice,means never......
add a amp stage but not a gain stage in the signal path way.