Suggestion:
It would be very convenient if the visibility setting for meshes / particles / actors was could be changed from Boolean to float: That way you could make an object invisible with a 0 setting and visible with a 1 setting.
This would allow simple lerp of fading in or out of meshes/actors/particles in BP without doing material instances. Also would allow the creation of partially transparent objects that have easier control.
Thx!
Matt