i dont own the game - but you can OC your GPU a little - like 1350MHz + 1500MHz RAM
also have in mind you ONLY USE dGPU IF PLUGGED IN - otherwise you use iGPU
also what RAM config do you have? 1x8G? that cripples the Acer Nitro 5 hard - i bought 2x 8G DDR4-2400 and now my iGPU and overall performance is pretty good!
PC: R7 2700X @PBO + RX 580 4G (1500MHz/2000MHz CL16) + 32G DDR4-3200CL14 + 144hz 1ms FS P + 75hz 1ms FS
Laptop: R5 2500U @30W + RX 560X (1400MHz/1500MHz) + 16G DDR4-2400CL16 + 120Hz 3ms FS