Why does Remnant II stutter during special ability casts on DDR5 6000?

During complex Boss fights, I noticed a slight hitch every time I released a major ability, which is lethal in fast-paced combat. I tried enabling low-latency mode in the drivers, but it didn't help and actually caused my mouse to feel floaty, making it unusable. I used the GamePP BIOS Load-Line Voltage Guide to increase memory voltage from 1.35V to 1.38V per HWiNFO and loosened tRAS to 80. RTSS monitoring showed frame times converging from 12-35ms to 10-15ms, and MemTest86 confirmed zero errors over six cycles with temps at 48-54℃ per HWiNFO.