When I rewrite the BAL tracker in nimbus EL, I discover that tests-bal@v7.2.0 missing test for this cases:

Condition: a contract creation address collide with existing account, and then the account is deleted or modified.

There are 46 test cases covering balance modification, the balance change appear in the BAL.

But there are zero test cases for the following changes:

1. nonce change
2. code hash change
3. storage change

I have not analyze if the protocol will allow the changes I mentioned.