Unusual workaround required to create an Adjustments preset in Photoshop Beta 27.3.0
I tried a couple methods to create an Adjustments preset in PS Beta 27.3.0. Selecting the layer and clicking the "+" sign in the Adjustments Layer did not bring up a Preset dialog. Nor did the Adjustment Panel menu list an option to add/save a Preset. Finally, I succceeded by (1) first clicking the "+" sign in Adjustments Panel; (2) then selecting the Adjustment layer and clicking Duplicate layer; (3) only then, as the confirmation/naming dialog opened for that action, a separate dialog blinked open to save the Adjustment layer as a Preset. After I named the Preset, it appeared at the bottom of the Adjustment preset menu.
Apparently, lining the layer up to be duplicated convinces the app that there is, indeed, a layer waiting to be saved as a Preset — assurance the "+" sign action won't act without.