Noble,
I don't actually put any work at all into Y6 SATS as I don't teach that year group.
However, just as a general thought - one of the reasons I find tracking (of whatever kind - continuous formative assessment, if you like) useful is because it makes each child's next steps so clear and it guides what I teach next. I know that I don't have to attach a 'level' to that for it to be useful, obviously, and in fact the levels are a 'byproduct' of the useful formative assessment, rather than levels telling me what I need to do next IYSWIM.
If you don't truly assess where each child is and what they can do until May of their first year, what is it that informs your teaching? Or is it that you 'teach the syllabus / scheme of work' to everyone and hope that enough sticks at the right level for them to move forward? Or is it that you DO do the formative assessment thing in every lesson, but what you don't do is any collection of that knwledge into a 'level judgement' of any kind?
Just curious, really. (Also, if you diregard SATs but do your own baseline assessment, surely your answer to the OP is 'the level they got in their baseline assessment', not 'their SATS level'?)