I am experiencing much improved render times with the beta version of multi frame rendering. Approximately 25 seconds for one of my personal projects I was testing it on, for a comp that would have taken 40-50 seconds on previous versions.
However on a particular composition I'm experiencing a significant delay after clicking 'Render' in the render queue, where the render queue is frozen before the render commences. The actual render starts approx 1 min 20 secs after I click the 'render' button.
Please note I'm not experiencing this same delay if I try to render the AE pulse benchmark project, which commences fairly quickly after clicking render.
Further details about the comp in my personal project:
It's a large project file with a lot of external media. The media was loading in from a Samsung T3 SSD.
I achieved better results (i.e reduced the time it was hanging) when I 'reduced project' to just the composition in question.
Another thing worth noting is that the composition in the original project file used expressions where colours of shape layers were tied to a colour picker in a separate comp. Upon 'reducing project', the links to those expressions were cut (28 expression errors) since the reduce project command doesn't include in comps which are only referenced by expressions.
System info Application: After Effects (Beta) v184.108.40.206 OS: macOS v10.16.0, RAM: 16.00 GB, CPUs (logical): 8