Deft makes/made a "brushable" and "spray" version of it's nitrocellulose lacquer. As you note the brushable version probably does contain retarders but they would be to slow the cure rather then getting a better flow. Though a case can be made for the two being the same thing.
In the last several months I've noticed the "spray" version has disappeared from the local shelves and has been replaced with the brushable version.
Deft being my nitrocellulose lacquer of choice I did some checking. They are only selling brushable now. They still advertise it as having excellent spraying qualities, and it is still thinned with lacquer thinner.
All in all a delayed cure can be of benefit since it will allow more time for any trapped bubbles to escape and more time for self leveling, hopefully making it even better resistant to orange peel.
As a side note, you are right on the money relating to thinning. Deft recommends, for better spray results, thinning 20% to 30%. Of course there is that first little bit, but that's another story.