I am having the same issue. I'm trying to do this process with Catalyst 3850/9300 stacks in install mode. Commands for this are roughly:
1 - copy scp://$xxxxxxxxx:password@x.x.x.x/image.bin flash:
2 – verify /md5 flash:image.bin (whatever hash value it gets from Cisco)
3 -- request platform software package install switch all file flash:image.bin auto-copy
4 -"reload" will reload the whole stack
For whatever reason, when I customize the fields to include these commands it ends up spitting out the monolithic or bundled mode config..