Are you exporting it as OBJ-only, or are you okay exporting it for a previous version which they will then load into their instance and compile?  

E.g. if you use Do $System.OBJ.SetQualifiers("/exportversion=2017.2") it will export the code in Caché 2017.2 format.  *However* this will not catch if you use syntax or updated APIs which were not supported in 2017.2.  You should really get a copy of the target version of software from the WRC (kits or containers) and at least do a compilation test there.