Hello, I’m one of SpeedTree’s artists! The seasonal timeline is not an animation of seasons that will be present on the tree. Instead, you’ll slide to the season/ color that you’d like and do an export to UE4. If you wanted to do a blueprint, you’d have to export out many version of the tree along the timeline and add your own animation. If you want the fallen leaves, make sure “show fallen leaves” is checked on.
For game grass, I’ve found the wind functions the best applied to a “hidden spine” with a “frond” setup. You will need to adjust the curves of the spine to get more movement possibly. We’d be happy to troubleshoot any problem if you need further assistance! Just send the file and request to support@speedtree.com