Round Trip needs to not disappear when it touches every projectile if you want to increase the durability. You can have a 1 low durability projectile touch it and it goes back to Trish, just like Vergil's and Cap's Shield Slash.
Also, s.L doesn't need 4 frames, j.S doesn't need a bigger hitbox, minimum air dash height does not need to be lowered, and Hopscotch already has a ton of hitstun.
My suggestions
+ Opponent's untechable time after ground throws increased by 20 frames.
+ Peekaboo has 80 frames of set hitstun. Decreases by 10 frames per every use in a combo.
What Low Voltage needs more than anything is better startup or recovery, imo. Maybe startup reduction too, but as far as durability goes, Low Voltage M and H tend to fly over most projectiles for a trade so it's not terrible in a firefight. Not great, but not terrible.