This script override selection mode in EditablePoly/UnwrapUVW AND allow to Convert subobject selection to an another in EditablePoly and Unwrap
Hit 1 or 2/3/4/5 ==> go in vertex/edge/..() mode
Re-hit 1 or 2/3/4/5 ==> go in object mode and you can select another object!
I have added a line, with "Max modify mode", like this, if your are not in "modify panel" when you select an object and hit 1 to set vertex mode, the script go automatically in the panel "modify"
Go in Customize User Interface, Group "Main UI", Category "zOffTy Tools" and set
1 for epoly_vertex