(WIP) Allow building light+heavy zipballs
(Note: This is previous work sitting from a branch on my local. I don't have my head in it at the moment, so not given a full description. Just pushing into a WIP MR so I can find it again later.)
(Note: This is previous work sitting from a branch on my local. I don't have my head in it at the moment, so not given a full description. Just pushing into a WIP MR so I can find it again later.)