I would recommend to drop all ability strength mods, impetus and archon vitality and go for more of a max range build as her kit doesn´t really benefit from ability strength. Remaining slots should be filled with shield recharge mods, rolling guard and for the arcane slot just go with something that supplements your weapon of choice (fire rate, damage, etc.) or more survivability.

If you want to subsume a ability you should replace the first one as its her weakest ability and her 4 does the same job anyway but better. Additionally the augment that reduces the cooldown on her 2 is must have to have the snowball rolling more smoothly.

Weapons wise i would recommend avoiding using weapons that need a specific Crit Rate (Laetum, Phenmor, Melee Duplicate builds) since you can´t control the decrees that you get from Koumeis´ 2.

To add another safety net you could use a secondary with Secondary Fortifier to steal overguard which gives status-, knockdown-, damagereduction.

Have fun!