I brew with the BIAB method in an aluminum turkey fryer pot. It's simple, cheap and effective. I don't worry about trub. Here is what I do.
1. BIAB mash in the kettle with a mesh bag.
2. Pull the bag, drain and squeeze. Then do the boil, add hops directly to the wort, no hop bags or spiders.
3. Chill the wort with an immersion wort chiller.
4. Line my fermenter bucket with a paint strainer bag purchased from the hardware store.
5. Dump the boiled, chilled wort into the fermenter bucket.
6. lift the paint strainer bag to drain. It captures all the hop trub.
Yes, all the grain trub goes into the fermenter bucket!
No, it does not cloud by beer!
The only cloudiness I ever get in the finished product is chill haze and that is because I have been using floor-malted grain like Maris Otter or Golden Promise without a protein rest. Nor have I been cold-crashing or using gelatin. But, I plan on using these methods to get rid of chill haze.
When the finished product is room temp, it's clear as a bell.
So, one last hurdle to clear for the perfect beer for me and this is dealing with chill haze.
I just don't see any reason to leave behind beer in the kettle because of the cold break. It does not seem to affect my final product.
And there are no aluminum off flavors.