AE1/RNG

Still a bit of a mystery but here are some of the community's findings.

From Ihavenoname248 at speedrun.com

It has recently been discovered that what gadget is being held affects monkey behavior. These effects are fairly small, but have substantial impacts in some notable places, including 3 of the most inconsistent monkeys in the game becoming much more reliable.

 -Dexter's Island, RC Car monkey. Much larger alert with the RC Car equipped. Can catch with water net.
 -Thick Jungle, UFOless. Equip with net and neutral double from very far back. 60-70+% consistent.
 -Dark Ruins fan monkey. Club or Radar are much more reliable than Net, as Net results in a very aggressive pattern.
 -City Park 1st/Specter's Factory RC Car monkeys. Equip the hoop and they run out much more often.
 -Other City Park RC Car monkey. Stand at a distance with the car.
 -Cryptic Relics river monkey. Keep the club equipped as much as possible to increase the odds of close side.
 -Primordial Ooze 100% first visit ending. Jump from the 2nd monkey with the stun club instead of the net.

Additionally, srgtsilent did some testing on Specter with different gadgets as well. Statistical significance is still low, but having the hoop or sling selected appears to give better luck on average than other gadgets.

Srgtsilent's spreadsheet about specter mentioned in above forum post.

0x0B4980

This memory address is possibly a cooldown value for the monkeys actions, freezing it to 0 will make the monkeys constantly sneeze, dance or be alert.

Freezing it at a higher value makes the monkeys do their actions less and less often.

This value changes at quite random, sometimes it'll stay on one value for 8 frames, sometimes 30.

0x0AE770

0x0B4950

Feezing these two values makes the first specter fight (2nd phase) repeat the same two attacks over and over again.

Freezing both to 0 makes specter do: pink lazer (left), chest smacking and repeat. If you then destroy the left arm, he'll just do the same but shoot with right arm.

Just freezing 0x0AE770 at 1111 will do laser (left), slam. after breaking the left arm, he'll repeatedly do laser on the remaining arm. odd thing though is that despite doing the laser attack, no lasers are actually shot

These two values change every single frame and seemingly most actions the player can do, will advance the values. Such as: Skipping the level intro, Changing gadget, Jumping, Pressing a D-pad direction.