What is the chance of finding a maximum/minimum size Pokemon when using a meal power that affects size?

Question

In Scarlet/Violet there is variation in the size of Pokemon of the same species. From this source, I am under the impression that the chance of a Pokemon being the minimum/maximum size is 1/256 each, assuming that every size value is equally likely.

There are the "Humungo Power" and "Teensy Power" meal powers which affect the size of Pokemon encountered of a particular type. When Lv. 1 Humungo Power or Teensy Power is active, what is the new boosted probability of encountering a Pokemon of maximum or minimum size respectively?

Answer 1

Alright, so... This one was tough.

When Pokémon spawn, 2 rolls occur for size. The rolls are 0 - 127 and 0 - 128

You have to roll 0 twice to get a mini, and you have to roll 127 and 128 to get a Jumbo.

This means that you have a 1 in (128x129) chance to get either or a 1:16,512

Now, the meal powers change your "dice" and improve your odds.

Humongo

Level 1: 64 - 127 and 64 - 128 which translates to 1 in (64 x 65) or 1:4160

Level 2: 80 - 127 and 80 - 128 which translates to 1 in (48 x 49) or 1:2352

Level 3: 96 - 127 and 96 - 128 which translates to 1 in (32 x 33) or 1:1056

Teensy

Level 1: 0 - 63 and 0 - 64 which translates to 1 in (64 x 65) or 1:4160

Level 2: 0 - 47 and 0 - 48 which translates to 1 in (48 x 49) or 1:2352

Level 3: 0 - 31 and 0 - 32 which translates to 1 in (32 x 33) or 1:1056

Source

You're going to just have to trust me on this one. It took me a while to figure this out because of the way the data is presented, and I had to come back to it with a refreshed mind.