The constraint is not 32bit floating point storage (which is ridiculously immense), but real-world bottle-necks prior to it.
One needn't adjust input trim/gain on a recorder if:
1) The total dynamic range of the signal will fit within the available dynamic range of the storage format..
(check, 32-bit floating point does this easily)
AND
2) The total dynamic range of the signal will fit within the available dynamic range through the recorder's signal path, up to the point where the signal is stored in that format..
(this reflects the most critical part of any specific implementation- the preamp and ADC performance of the specific recorder)
AND
3) The actual upper and lower dynamic range values of the signal fit comfortably within the upper and lower dynamic range limits of the recorder's signal path, up to the point where the signal is stored.
(this is about shifting level of the source if necessary to comfortably fit requirement 2, by making sure the signal does not overlap or exceed either end of the available range)
32-bit float storage solves the first problem. The available storage range of 32-bit float is effectively unlimited for audio purposes. Practically, it will depend on how well the other two things are handled in any particular recorder touting the benefit of 32-bit floating point storage.
The problem is accommodating the total output range of a source to the available input range through the recorder (which has been steadily increasing as tech advances, yet remains limited). Most of the hoopla from manufacturers and reviewers thus far has focused on the "wow factor" of the second part of that statement, while not talking much about the "real world" constraints of the first part. Those of us calling for temperance understand that the first part is really what is going to matter. And that will boil down to a performance measure of each individual recorder which is rarely specified clearly by manufacturers.