After some testing, a Float of 55.0 works in that variable. My rotation grid snap is set at 5 degrees, and at 90 degrees the spline point was vertical, 90 degrees up from horizontal.
I’m using Ryan Laley’s spline tutorial (Unreal Engine 4 Tutorial - Splines - Spline Meshes - YouTube) and was able to insert this after the Set Collision Enabled node and before the Set Forward Axis node.
Everything working well so far.
Edit: attaching a higher res image of LostScout’s as it was difficult to make out.