Krusty, from what I know, 2k and 4k eggs were rarely used. But, I don't know much about B-24 loadouts of the ETO. Most information I read comes from pilots/crewmembers, stories, etc. from the PTO, where large bombs weren't really needed.
Thing is, the B-24J can carry the large bombs, but keep within its standard combat weight loadout. The B-24 "can" carry 18,800lbs or so, but rarely did it ever go about 12,800lbs.
Most of the time it just depends on what the mission called for.
The Lanc will still be used, because neither the 17 or the 24 could carry 14000lbs of bombs further than short range. Even though Im a huge fan of the 24, Id much rather take a Lanc if I needed the added bombload.