Pancha said:
It also lends itself to the idea that starting with a 50 mm hose in the beginning and then transitioning to a smaller hose is a more effective method of dust collection.
Definitely.
You might find more information by looking at dust collection ducting design - it's all about volume moved and the velocity of the airstream, and changing the size of the duct (hose) such that it is narrower further away from the extractor is one of the main ways that you retain a well functioning system when increasing the length of the ducting.
Typically, small shop systems will start with a 6" duct at the extractor/cyclone, and maybe for the main trunk, with 5" duct coming off as branches, a 4" or smaller used at machines depending on their individual requirements.
The larger diameter of duct/hose at the tool end, the higher the velocity needed to move the volume necessary to extract dust efficiently from the tool.
I assume that's why tools like the Kapex work best with the 36mm hose - it hits their sweet spot with regard to volume and velocity; a 27mm hose has more velocity but not enough volume, and maybe the 50mm hose has enough volume but not enough velocity?