Reduce IUK size
This is about researching low-hanging fruits to reduce the size of our IUKs in order to be nicer to users with lower amounts of RAM (strictly less than 3GB) and users with not very fast Internet connection.
This is related to #15281 (1BigIUK) because of the larger IUKs. Once we have it it really seems worth at least picking the low-hanging fruit among size optimizations.
Yes, maybe… but the marginal benefit (relative to the total upgrade download time) brought by such optimizations will actually be lower once IUKs get bigger. So I guess it could be worth giving a quick try to the low-hanging fruits I've identified on the subtasks and check how much space (and thus download time) we would save, before even evaluating whether these tricks break anything we care about. Now, no big deal if we don't do it IMO.