There is no spillover when loading different Programs. You have FX A and FX B within a Program, so you could build a program in a way where you bypass/activate the A/B effects to achieve something similar to spillover.
The xfade routing mode would also be a good option to explore. See page 38 of the manual: https://s3.amazonaws.com/com.eventide.downloads/Product+Manuals/EclipseUserManual.pdf
Your best option for an FX processor with true spillover would be the H90. It can achieve a lot of the same things that the Eclipse can do.
