Those temperatures are a little high. I would be try to keep the max temperature in the low 80s, with only the odd, short duration spikes above that. Check if you laptop's BIOS has a place where you can modify the fan speed control thresholds.
those temperatures while playing PUB is a bit too high but normal, try WOT it uses just one core and heats up kaby lake cpu's up to the max.
All you can do is undervolting from negative 0.135 to negative 0.150mV it will reduce heat it will reduces TDP usage to less then 45 so your cpu will not get throttled down to 2.7-2.8Ghz
yeah, i downloaded intel extreme utility and undervolted, the temperature while playing pubg went from 85°- 90° to 79°C