Ah, the old 'Reading the post heading' trick eh?

OK fair do's.
Yes, you can have something that trawls the SIT entries and 'copies' the information to an element entry. The issue as I see it would be around covering all the possibilities for creation/change/deletion of the SIT, and making the equivalent result happen on the element entry. In that respect, I think element batches would be OK unless there was the need to end-date or even purge something. I'm not 100% convinced that you can do that sort of stuff via BEE. Bear also in mind that SITs are not truly date-tracked, whereas element entries obviously are: so you have to think very carefully about the possible scenarios that can happen to an element entry in terms of changes, and then try and relate each of those to an equivalent event on the SIT.
Edit: I imagine that being to do with overtime, the resulting entry would in all probability be a non-recurring entry, in which case the only thing you might need to worry about is correcting things like number of hours, hourly rate etc. So BEE might actually be a good move, as my learned friend opines!