The flow of water coming off the tiny holes you will have to look at one did you will have the one of water coming off the needles will still get stuck in awhile it probably wont disrupt the cones wont disrupt the roof though the gutter helmet that doesnt.
Have a big pine overhanging a back room.
The gutter guards do work better than screens.
I used cheap plastic ones from a lumber yard & they work fine.
Some needles get in but no cones.
Still have to check from time to time but I rarely have to clean in less than a years time.
Best regards