>>51642053At this time we don't have enough data to draw a conclusion.
I've been trying the "waste 10 Poké Balls" method just in case it turns out to be true, but if not, it's only 10 Poké Balls.
If I had to guess based on the research, the internal multiplier probably starts at 1x then increments 0.1x until you get a 2x chance on the 10th throw.
If there is such a bonus, the factor isn't itself known with any certainty, and especially not if it's active outside of raid encounters.
https://thesilphroad.com/science/raid-bosses-easier-catch-later-encounter>It’s unclear what factors affect the multiplier: the number of Premier balls thrown, balls remaining, total number of times the raid boss has been hit, number of successive hits, or some other factor. 