As suggested I did the research at SV site.

They have such a feature on the $700 version, but not the three $200 or less versions.

They restrict to 10 tracks on the timeline for the three $200 or less versions, unlimited on the $700 version.

They have something included called HitFilm. I reviewed the producing a gun shot effect video, and it looks pretty awesome, but I suspect a lot of this we can already do in AS. I haven't explored trying to rotate a particle effect in 3D in AS, as seems to be simple to do in SV.

There has been no feedback from AS for quite some time, no announcement of a service release or a version release anywhere in the future. And I'm just trying to figure out if I should stay here hoping my issues will be fixed before my next major project, or if it is time to move on.  The whole project-in-project feature of AS I absolutely love. There is a lot about the Library I don't like though.  And I have yet to be able to burn a working BD.  Hence the exploration of feature comparisons.  I would have difficulty giving up project-in-project (sub-movies). As others have described, I use them extensively, and to several levels.