Just keep in mind your solution means all +myjob/add comments are published which may or may not be desired behaviour. /add comments are unpublished by design and it's not a shitty design, there exist no reason to expect that all comments to a job are readable by all people involved and changing this behaviour makes it useless for certain tasks such as anonymous voting, conflict resolution etc.
The cleanest solution here is most likely to have +myjob/cc publish the job as well as change &FIL_PUBLISHED to not display comments from staff unless they also have the no_inherit flag.
&CMD_MYJOB/CC [v(JOB_GO)]=$+myjob/cc *=*:@switch [not(u(%va/FN_GUEST,%#))][setq(0,u(%va/FN_FIND-JOB,%0))][isdbref(%q0)][or(and(u(%va/IS_PUBLIC,%q0),match(get(%q0/OPENED_BY),%#)),u(%va/FN_MYACCESSCHECK,parent(%q0),%#,%q0),)][not(u(%va/FN_HASATTR,%q0,LOCKED))][setq(1,map(%va/MAP_SOURCE,secure(trim(%1))))][setq(2,member(%q1,#-1))][not(gt(%q2,0))]=0*,@pemit %#=This command is not available to guests.,10*,@pemit %#=That is an invalid job number.,110*,@pemit %#=[name(%q0)] is not yours. You can only modify your own jobs.,1110*,@pemit %#=That job is locked and cannot be changed at this time.,11110*,{@pemit %#='[extract(secure(trim(%1)),%q2,1)]' is not a valid player or jgroup.},{&PUBLISH %q0=1;&opened_by %q0=[setunion(get(%q0/opened_by),%q1)];@pemit %#=You have set job
Used MAIL_ACCESS as the staff check, replace with whatever you feel is appropriate.
&FIL_PUBLISHED [v(JOB_VA)]=or(and(u(%q0/PUBLISH),not(u(%va/MAIL_ACCESS,extract(get(%q0/%0),3,1,|)))),hasflag(%q0/%0,no_inherit),u(%va/FN_MYACCESSCHECK,parent(%q0),%#,%q0),t(member(u(%q0/OPENED_BY),extract(get(%q0/%0),3,1,|))),strmatch(extract(get(%q0/%0),3,1,|),%#))
Tangentially, using the numbers 0-4 as your variable names should count as a crime against humanity.