Motion Inconsistant On New iMac Pro

OK, so here's the thread to discuss how and why Motion 5.4 is so inconsistent on the iMac Pro. I ran tests on it and my old late 2013 MP. Some projects exported faster, some exported slower, regardless of codec, but seen most dramatically with H.264 exports (unlike what I'm finding in FCPX and Compressor, which are both MUCH faster on the iMP).

Playback of both light and heavy projects, at least for me, seems to be the same. As if the iMP offers zero advantage for this one application.

So what's the deal with Motion? Is it not fully optimized to take advantage of the iMP hardware properly? What's the deal?

meanwhile …
The highly prestigious German ACT Robin Kurz told me:
CPU computes Behaviors & Simulations
GPU computes frame content

So, in my humble understanding:
A Motion project with a few objects, but physics & hundreds of behaviors should run faster on a better CPU equipped Mac …
A Motion project with thousands of layers and a handful of keyframes should run faster on better GPU equipped Macs

… but
a very thin database doesn't reflect this. As board member pszilard kindly told us here , a simple MotionProject needs 14.5min on his iMp - which is about 300% faster … compared to my low-powered 2012 MacMini - boohoo:

One should expect an antique DualCore i5 WITHOUT any designated GPU should be missed by the country mile by an 8/10core Xeon + Radeon Pro Vega beast …

Or, for the few active Motionists:
nest 3-4 levels of Attached-to Behaviors into a project = brings systems like mine to an instant halt. Lots of computation, no doubt, when you re-enact a dynamic system, a Triple Pendulum - but no rocket-science, hm?

Just some educated guess, or, better, questions:
Does Motion make use of cores anyhow? Of a GPU as a 'co-processor'? Can Behaviors and Simulations been 'split' onto several cores?

In my amateurish ignorance of any programming, hundred cubes, affected by gravitation (as in one of my stress-tests) should be easily spread on several cores, esp. considering there's no object collision detection (=no 'interaction' btw objects) in Motion … each cube gets its own 'calculator', the more computation units the faster.

Not so.
… as it looks.

And, just for comparison, board member Axel kindly informed us about Eevee, a renderer in Blender, which allows Volumetrics, one of the Holy Grails in 3D/CGI … in real-time. <sigh>

… a topic of niche interest, have to admit, but it would be … say odd, when the 'Effects Machine' in the proNLE-universe of Apple still is on code and hardware standards of 2006 …

To push around a few boxes and glyphs in a lower-thirds, that's enough … but complexity in actual screen-designs (3D, translucency, live video as textures, etc, just watch any NFL/Soccer/sports TV report) asks for more.

And I'm not speaking of a fully flavored CGI system as Blender, C4D et al …

hmm …?