So basically
1)bitmain had and still has the ability to cheat on hashnest.
2)bitmain had and still has the ability to cheat on bitdeer.
3)bitmain had the ability to use its covert asicboost.
4)bitmain and others had the ability to manipulate the tx fees as per this thread
https://bitcointalk.org/index.php?topic=2634505.0and not only did that ability exist I had concrete evidence that was being done by various pools back in 2017
Bitmain apparently no longer owns HashNest (BitDeer is owned by Bitmain). I was talking with the HashNest admins. They are still in close business relationship but are no longer the same company.
Also HashNest has been updated recently with new miners, S15 is out and they just launched Z11 preorder for end of the month