Ending or Modifying Automatic Transactions

[rtjmay]

Hello,

I have an automatic transaction that allocates my salary into various 
virtual accounts:

= /^Income:Salary/
    (Funds:Savings)           -0.60
    (Funds:Donations)        -0.05
    (Funds:Spending)         -0.35

My asset allocation requirements change from time-to-time, but I'm not sure 
how to end or modify the automatic transaction with retroactively affecting 
all the previous salary entries? I've tried creating a new automatic 
transaction later in the journal to negate the previous transaction, but it 
generates very messy register output with lots of redundant postings:

= /^Income:Salary/
    (Funds:Savings)           0.60
    (Funds:Donations)        0.05
    (Funds:Spending)         0.35    
    (Funds:Savings:Special)   -0.50
    (Funds:Donations)       -0.05
    (Funds:Spending)        -0.45

Is there something similar to apply tag/end tag for automatic transactions?

Thanks,
Ryan