Wrong. The mixer is floating point and you are not in danger of losing any transients. If you are talking about printing a mix to a 32 float file - that is a different subject and not what the OP was asking about. I mention that this had some potential benefit in an earlier post.
Again, this is about PRINTING a mix to a 32 float file. The OP asked about tracking to 32 bit files. Also, as long as there are no ‘overs’ and the peak level is at least -20 dBfs or so, it should not make any audible difference anyway.
So? Print your stems @ 32 float (not that you should hear any difference versus 24 fixed, assuming your gain-staging is anywhere near decent). You still have no need to record at 32 float when tracking, and again, you are talking about printing mixes, not tracking.
The quantization distortion you speak of (32 float to 24 fixed) is well, well below the limits of human hearing, not to mention the ability of the gear to reproduce it. Dithering, while the technically correct thing to do, will not make an audible difference in this case either. Blind tests will prove this, though some are not interested in the truth.