I have not played plinko for that long. but atleast 10-15 times by now. i think that seed changing is essential.
I understand the feelings u can have for a seed. But when i started changing seeds between 350-800ish i had some hits, iam playing around with the 4-6k balls pr seed to see if it helps the chances, but i think its in this "ballpark" (u see what i did there :P).
Feelings doesnt make u money and hope doesnt either, so change your seeds imo. I started to change seed 150balls after a 130x hit if it was due before 300 balls. i have had some insane streaks gl all