Asus Maximus Extreme IX liquid metal

[parmi]

​​​​​​​Specs:

• CPU: i7-7700k @ 4.20 GHz (Turbo boost: 4.5GHz) [delidded]
• Mobo: Asus Maximus IX Extreme
• GPU: Gigabyte - GTX 1080 Ti Waterforce WB Xtreme Edition 11G
• RAM: 32GB - G.Skill - Trident Z RGB - DDR4 3600Mhz - 32GB (8GBx4) - 16-16-16-36
• PSU: Seasonic - PRIME 850 W Titanium
• Custom Cooling system:
• Radiator: x2 radiator (520x30x60mm)
• Radiator FAN: x8 Noctua (120x120x15mm)
• Pump: EK-XRES 140 Revo D5

I built my PC 5 years ago (specs in my profile), never changed neither thermal paste nor cooling liquid since then, temperatures rarely exceeded 50C (while gaming).
Now I feel the need to overclock my system, to improve performance in some games (specifically Valorant, which is particularly demanding with the CPU).

I did some tests at 5.0GHz and this is the best overclocking setup I have found so far:

• CPU ratio: x50
• Cache ratio: x42
• Vcore in BIOS: 1.415V
• Vcore mode: Manual
• XMP profile: Disabled
• iGPU: Disabled
• LLC: 5
• AVX offset: x0
• Vcore under stress (measured*): 1.411 V

*FLUKE 179 multimeter using the average function and measuring for 1 minute

With this configuration after 17 hours of stress test with Prime95 (Blend mode) I got an error (Rounding was 0.5, expected less than 0.4) on core 1.
Now I'm running another Prime95 session with the Vcore at 1.420v

Once I find the stable vcore, I would like to switch to adaptive mode (and playing with the offset) to reduce CPU stress and increase CPU life expectancy.

What do you think? is it a good idea to use adaptive mode instead of manual mode?

In any case after 5 years I think it is time to change the thermal paste, coolant and thermal pads (although the temperatures are still good).
I would like to use liquid metal instead of thermal paste for the CPU, but I cannot find information on the material of which the Maximum Extreme IX (bitspower) monoblock is made, I think it is nickel-plated copper, but I could not find official information about it.

Can someone please tell me what material is it made of?

Also where can I find the dimensions for the thermal pads (thickness, length and width)?

Any suggestions are appreciated!