Scrips can't set/modify TimeTaken


I’ve tried to write a scrip that sets a transaction’s TimeTaken value
from mail headers. However, I had to find out that “Transactions are
immutable” (see sub _Set in While I generally
agree with that sentiment, a newly created Transaction (or at least the
TimeTaken value) should be mutable until it is completely processed
(i.e. all scrips are done). Now I’m wondering, has anyone run into the
same problem before (didn’t find anything in the archives)? What’s the
suggested solution?