I have the feeling that super-steam generates a more saturated environment than steam-bake.
that's only a bit of a guess.
the way to solve this would be to measure the condensation and water loss from the reservoir at the same temp-time
for super steam and steam-bake.
I know many expensive commercial combi-ovens let you set the saturation for the steam at any temp.
Ive also noticed that at lower temps i.e. 225 steam-bake vs 400 steam-bake more water is used from the reservoir
and more condenses in the oven --- in your pan and down to the small reservoir.
I think @blue_dolphin pointed this out up-thread. Ive only used 225 steam-bake once and was surprised.
I think two small pans have to take more time in the oven for a given result than one small pan.
there is a thermal gradient and it would take more energy i.e. time to get both pans to the state of a single pan.