I have had successful spawns without nest with the male and eggs floating all over the surface and without a males-however, survival rate and higher numbers of fry will be seen in spawns that use a nest.
When the male picks up the eggs he will encase them with a bubble so they will float, and usually later he will make a nest and put them in the nest.
I have had eggs hatch that laid on the bottom after they fell from the nest
I have artificially hatched eggs without a male in a shallow cup
I don't rely on the size of the nest or building of the nest as an indication of breeding readiness.
I have had successful spawns without a nest in the tank, I have a male that will not build a nest until he has eggs in his mouth and is one of my best breeders, he also is one that moves his eggs often.......