Completely agree on the granular access issue, companies with much smaller engineering teams manage to do it! I did use the import tool with no trouble but it

Completely agree on the granular access issue, companies with much smaller engineering teams manage to do it! I did use the import tool with no trouble but it was about 10x less data than what you have. Given the 2.5GB/day bandwith cap of the gmail API/IMAP you might really be better of with the takeout option though, doing the whole operation from a machine possibly in a datacenter with a good uplink.