z390 V1.4.03 now has integrated support for the new ZSTRMAC structured programming extensions for conditional macro assembler. So open code and macros can now be assembled and executed without translation using the extensions such as AIF, AELSEIF, AELSE, AEND AENTRY, AEXIT, APM, ASELECT, AUNTIL, AWHEN, and AWHILE.
For a few actual examples see the utilities in linklib named RTGENDIR.MLC, RTGENCMP.MLC< and RTGENDIF.MLC which all use ZSTRMAC extensions now to eliminate the need for any AGO or macro labels. These utilities are used in regression testing to compare all the files in two directories and list just those files which have differences and also show file totals.
Just for fun the very old demo DEMOM8Q1.MLC has also been rewritten as DEMOM8Q1.ZSM using the ZSTRMAC extensions to remove all AGO and macro labels. It can be run on v1.4.03 using the command: mac demo\DEMOM8Q1.ZSM