BU takes an existing hard consensus rule which controls much more than just the economic issue of more transactions, and opens it up to manipulation in a way that could have a myriad of negative consequences.
The blocksize metric controls:
- CPU consumption
- Storage space
- Orphan rate
- Potentially stresses every analysis and blockchain app ever written trying to manage a massively huge database
BU doesn't change the blocksize to a fixed size but, instead, turns it into a dynamically adjustable value which can be manipulated by cartals. These cartals might manipulate it to make the blocksize much, much, smaller demanding ransom or to gain some other leverage or pressure.
They might also manipulate the blocksize to be much larger and fill blocks and the network with junk transactions in an effort to destroy competitors.
Much larger blocks would quickly lead to centralized data centers running nodes and miners; making an easy target for governments to enforce blacklists and AML/KYC .
These are just some of the risks presented by BU. The fact that the team developing it has made massive changes to the source code, outside of the pre-existing peer review process and testing environment, this alone, disqualifies BU as a candidate.