Limiting character to 180 degree turns

side scrolling 3d project. The character can move freely along the side scrolling ground like in an old school beat’m-up like Double Dragon.
I’m trying to limit the direction the character faces to 2 directions while still moving freely. If the character is moving along the plane in any direction from 0 to -180 it should be rotated to -90 on Z. If it is moving in any direction from 0 to 180 it should be rotated to 90 on Z.

Right now I’m doing this by checking the actors forward vector. If the range is between -1.0 and 0 I turn the Mesh Component (not the whole actor) to -90. Else to 90.
Works fine but it flicks real fast. I tried using a rinterp but it looked off somehow.

How do I get an actor to turn using it’s turnrate, but limited to “left and right” while still being able to move about freely on the floor plane.