No need to support the scoreDrl field, because WB usage always uses kjars.
The new field ksessionName's value must match a kession name in META-INF/kmodule.xml.

So it would preferably be a Combobox, with all possible values.

Note: It can also be left null (element not added in xml, so not empty element), in which case it defaults to the default ksession in kmodule.xml. It should probably default to that behaviour, but in that case show show what the default kmodule.xml in xml is (and show red if none is set as the default).

PS: How does validation work? It's possible that a user creates a solver conf first, then a DRL and then goes back to edit the solver config to use that DRL. To have this be possible, a solver conf must be save-able even though it's not a valid one yet... Some validations are Save-preventing, others are not...