HI, tks for the guidance 1st. But i have tried to adjust to memory to 2000 before, but the hahrate seem is nothing diff, my current core temp is around 55c but the memory temp is higher than yours which is around 88c.
If you increase memory clock then you need to increase power, set the power limit to from 60 to 80. You need to adjust based on the hashrate you are getting, memory overlock at 2000 is too much, I would not risk it, I leave mine at 1500mhz because my memory temp is below 80c.