Razer Blade Pro 2017 - FPS/Crashing issue

Hey all

Hoping someone can advise if there is anything I can do to try and fix this issue I am having with my RBP-2017. Series of events is as follows:

I play 2 games quite regularly, Subnautica and State of Decay 2. They used to run ok on this machine.
Recently (6months -> 1year) they've been getting serious FPS drops every minute to 30 seconds or something like that. Then every 15-30 minutes the games will crash out.

A while ago I got the dreaded battery bloat issue, I haven't been able to find a replacement as of yet so it currently doesn't have a battery. I've researched and found that this has caused issues on different systems with the laptop always thinking it is out of power. Could this be the issue here?

System Information:
- Windows 10 Pro x64 (Version 10.0.19042 Build 19042)
- Processor Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz, 2801 Mhz, 4 Core(s), 8 Logical Processor(s)
- BIOS Version/Date Razer 2.00, 12/1/2017
- Installed Physical Memory (RAM) 16.0 GB
- GFX: NVIDIA GeForce GTX 1060 (I believe these Razer machines also have an onboard Intel gfx processor).

What have I tried so far?
Standard checks:
- All drivers installed and up-to-date
- All windows updates installed.
- Reinstalled all drivers.
- Reinstalled games.
- Wiped entire machine and rebuilt.

Power mode:
- Set to high performance.
- CPU performance settings are 100% min and 100% max.

Diagnosis so far:
- I noticed that the Event viewer is logging a few errors about processors being limited by firmware. Apparently this is something to do with Intel SpeedStep which is disabled, doesn't seem to have had any effect and warnings still appear so could be unrelated.
- I cannot see any specific error logs that happen when the games crash.
- Ran GPU-Z and could see that it was reporting the "perfcap reason" as "pwr". Suggests that the voltage limit is restricting the processor but again could be unrelated.

Anyone got any ideas? If you need any more info please let me know and i'll update!
Thanks