24H2 Crippled My Laptop; What Can I Do To Regain Lost Performance?

I already updated iGPU, Wi-Fi, Bluetooth, and dGPU drivers manually (some other drivers Windows updated them); disabled or at least forced many new processes and apps to run manually instead of automatic; and I'm considering to bypass Optimus by connecting an external monitor via HDMI so the iGPU will no longer bottleneck my laptop due to some system resources being given to it instead of my CPU. Sadly my gaming laptop is almost 6 years old and it started to degrade in performance a bit over a year ago, with the thermals suffering from age and heavy use, along with me switching from Windows 10 to 11 as the latter has more CPU overhead and isn't fully optimized for older chips like mine. I previously mitigated performance loss by re-applying thermal paste, undervolting and power limiting both CPU and iGPU (dGPU can't because Acer locked those at vBIOS level), and use a cooling pad that also elevates the PC; sadly now with 24H2 adding even more overhead, I have to do everything else I can to save it.

https://www.overclock.net/threads/will-igpu-intel-hd-grahpic-will-affects-the-cpu-overall-temps.1305780/

https://linustechtips.com/topic/563010-does-integrated-graphics-affect-cpu-performance/