Hi there,
im making a tool that use spline mesh component as well and yes, 5.1 make the spline VERY SLOW, almost impossible to move points.
it work flawless using 5.0 or less.
BTW; check the Add Splne Mesh Component Node inside the blue print editor, turn OFF the collision.
That will make the pline a lot faster (this trick work on 5.0 but it doesnt not work in 5.1). anyway, you can try and maybe it will help a little.
waiting for Unreal response as wel…