Beyond 'Merging Radius' and Invasion scarab interaction

The beyond/alva/evolutions strat is very powerful and popular, yet i noticed that many don't take any merging radius on beyond - is it because merging radius has no effect on beyond scarab of invasion since it's a set value?

I realize just how obscure a mechanic beyond portals really are, hopefully someone can clarity. I wouldn't mind having an extra 6 points on the atlas to spend on something else if it doesnt work!

Could be that there is some level of saturation where further radius is not particularly useful, or there are better options for adding mob density etc. I'm not exactly sure, but you might be able to get an answer in the gameplay section.

its a density thing: it would be wasted to get more radius, as you are already spawning nearly the maximum you can.