The reversal process (Reversal Entry, Reversal-Post, Gen. Jnl.-Post Reverse) needs a mazor refactor in order to be easily extensible.

If for instance you have an extension with entities resembling eg. Customers or Vendors, with its own respective ledger entry logic posted along side with G/L Entry, its an extensibility nightmare trying to keep your code out of the base application in case you need reversals (which in such a case its absolutely certain that you need reversals).
One must resort to solutions like single instance codeunits and the whole process quickly becomes unnecessary complex and error-prone.

Please consider a full refactoring ,new events or changing existing ones wont help.