I just checked only self buffed to use ice lance to prolong Icy Veins duration using MI with multistrike and then with haste glyph. My images made 260-290k dmg total when using the glyph with multistrike. And 250-260k dmg when NOT using the multistrike glyph. I did several tries and seems Multistrike is better for MI than Haste.
Currently stats without procs and spells, only self buffed are 6& haste and 22% multistrike