Lens recommendations for wildlife - 50-200 2.8 versus 300 F4

All,

I recently went on a trip with the following gear and it was a bit heavy and I have another trip coming up late this year and I'd like to maybe reduce down the weight, and improve IQ.

• Om1.2
• Em1.3
• 12-40 2.8
• 40-150 4
• 150-600 5-6.3
• A few pancake primes

The next trip will be with much worse lighting conditions, rainforest / pantanal, and the big white 150-400 is likely out of budget although maybe I can be convinced to sell 150-600 and some other gear to go for it.

I've always wanted a 300 F4 for the size, weight, and image quality. (As well as learning to use a super tele prime; I've always looking at renting a Canon 600 prime with my other gear) But the 50-200 2.8 is also looking ridiculously good, and the 1.4x and 2x TCs make it super intriguing.

Thoughts? Suggestions? Or should I just be selling blood / plasma to get big white and ditch the 150-600?