What Game to Use

TLDR: What game is stable enough to test undervolt/overclocks on?

I recently got a 13900k and a 3060 TI. Yes, I know the GPU is completely unmatched for the CPU. But, it shouldn't cause any issues, unless i'm wrong.

While undervolting/overclocking the 3060ti, I've been playing Black Ops 6. I am going for just a middle of the ground undervolt while maintaining a modest overclock. I have 2 questions.

Question 1: What game should I use to really test it? The reason I ask is because Black Ops 6 keeps crashing and I'm not always sure if it's their shittily optimized game or if it's my overclock/undervolt.

Question 2: Where can we see what the actual rated for Core Mhz and Memory Mhz is?
the card is this: ZOTAC GAMING GeForce RTX 3060 Ti Twin Edge OC LHR

On the webpage, it says it's rated boost is: Boost: 1695 MHz

But I'm well over that. I /believe/ I can run stable at 1910 and .875v So I don't know where I'm at on how much over I am or not.

Thanks.