An idea to enable Beast Mode for Layout’s SU reference model render updates.
Basic understanding: (Pardon my limited technical knowledge, I am a user, not a programmer)
1. LO, like most CAD software packages uses a Single Core to process data.
2. I believe the reason for not utilizing Multi-core processors is that a single 3D model environment cannot be parsed out easily to different cores for parallel processing and would likely end up with conflicts, inconsistencies and crashes.
3. As a result, LO updates one SU window at a time in a serial processing fashion on a single core.
4. On faster computers with Raster, this is typically fast enough, however, on Vector or Hybrid the updates tend to be very time consuming, especially if you have a large LO file with many pages and many SU windows to update.
Workaround solution:
1. Add a Beast Mode when starting LO that can be activated to enable the following.
a. For every SU window, make a temporary copy of the referenced SU file, preferably in RAM or in Virtual Memory if there is not enough RAM.
b. Assign each SU Model/Window update to a different core as well as each pages graphics to a different core.
Theoretically, this would allow for parallel processing within LO. The speed improvement for rendering updates would be on the order of “X” times the number of cores a computer has available. On my system that could yield a 20x or 2,000% increase in speed. If an entire LO file took 5 minutes to update, that could get reduced to 15 seconds. For someone with a Ryzen Threadripper Pro, that could yield a 192X or 19,200% increase in speed. That same file update might be able to be reduced down to 2 seconds… (or most likely the time it takes to update the most complex SU window in the LO file on one core)
Of course, other bottlenecks will show up, like RAM and Storage space and Storage Speed bandwidth, CPU Temps, and the resources the OS takes up, so the management of how many cores to actually utilize would need to be balanced against the other resources available. But if even a 5x increase were possible, it would be amazing! 
Here is how the current level of resource utilization looks on my system while rendering SU windows in LO where I average between 8% and 12% utilization with only LO running. I assume LO is only using 5% (1 out of 20 cores) and the rest is for other Windows processes.
I dream of the day that the utilization looks more like this: 
I know this is not the most elegant solution, but is simply a way to fully utilize the raw power available with today’s computers, hence the Beast Mode Name.