Frame Spacing reduces Drones, Swarming & Varroa?

hello,

Instead of taking a Thread off topic, I decided to open a new Thread, but also about Frame Spacing.
Scroll down to the diagrams, where the claim that 12 or 13 Castellated Spacers with only 10mm space between them (and 6mm at the ends) reduces Drone brood.

If this is true, does it also not follow on that it could reduce Swarming (or at least help), and then as Varroa so much loves Drone brood, could it also mean that the reduction in Drone Brood helps to control Varroa?

Does anyone have hives with different frame spacings in which they have noticed one hive producing less Drones, etc.


Please help.
Thanks!

I didn't find the right solution from the Internet.

References:
www.beekeepingforum.co.uk/showthread.php?t=41160


whiteboard video examples