Video Editing - Fading in overlay png images using keyframe Opacity - best workflow?


What is an efficient workflow for fading in and out overlay images to a video?

The attached image shows how I do it now.

You can see two strips, in slot 1 there is a video sequence from NASA TV, and in slot two a png image done in Inkscape.

I add a key frame for the opacity (=0) where the png starts and then I step up the cursor 24 frames and add a second key frame for the opacity, now =1. This works fine, comes out really nice. BUT, it is tedious, especially when you have a lot of images to fade in and out.

Is there a better way to do this?