In a huge number of cases, programs using relative branch are not base-less. They have no "code base register" but that does not mean they are base-less. For the most part, z/OS has simply decided that we will not worry about "no base register at all" cases when customers use our macros. We expect addressability to a static area where literals go. So no "code base register" but a "static data base register".
I didn't follow how LOCTR would help unless accompanied by LARL. Without the LARL, you still need addressability to the area built from the data within the LOCTR section. And if you have such addressability then you could have your LTORG within that LOCTR-defined area too so that anyone's macros could use literals. Peter Relson z/OS Core Technology Design
