Parameters Ignoring Keyframes / Waypoints, and Multiple Timelines

Hi: I am making much progress with Synfig, but still having some challenges. I thought I understood parameters, but am now perplexed! I am using development version 1.3.33 on OSX. Essentially, I want an object to appear later in the animation and have been trying different techniques to achieve this. One option, I think, is the Behind parameter in Blend Method. But, if I choose Behind at 0s, and then choose Composite at a new Keyframe at, say, 20s, the Behind parameter selected at 0s resets to Composite. If I were to do the same with Opacity, it would not reset. Can I not have multiple Blend / Behind settings at different Keyframes / Waypoints? Simply put, I want to have an object remain invisible for, say, 20s, then appear at full opacity. A related question: I understand that I can import multiple Scenes into one Document, but can I have multiple Timelines in one Document–happy to be pointed to existing help. Thanks very much.

You could only animate its opacity, couldn’t you?
Value 0.0 at beginning and value 1.0 at 20s. Don’t forget to use constant interpolation, as it allows you to make a sudden change of a parameter value.

Yes, I could only animate Opacity – I assume then that Blend and other cannot be animated with Keyframes / Waypoints? And yes, I edited the Waypoints for Constant to avoid the object easing in.

The challenge is building the animation architecture sequentially so that Keyframes / Waypoints don’t interfere with animations added later, which is why I am curious if one can have multiple timelines or canvases within one document.

Thanks again for the continued support.

You can animate blend, but, as it is an enumerator parameter (ie, a list of items), each item is bound to an integer number. So if interpolation curve/graph creates real numbers, they’re “rounded” (or "trunc"ed, I don’t know) and then parsed as an one of the enumeration items.