We currently use Facebook messenger and are going to be migrating over to Discord.
And I bet you wonder why people think you have no clue what you're doing, too.
Why are Asgradian things put into google drive, or google to metric who looks at what, for how long? Without being invasive(and I'm itching to be invasive, just to see how bad it is in there) I can confidently suggest the the 2TB HD in the server hosting this should be able to hold such readily, keeping everything "in house". Same with the comms platform - that has no rights, considering the potential scope of conversations, sitting in a third parties data mine ready for their use. It should be all happening in house - That's how you prevent third parties having access to data they shouldn't have - you don't give it to them willingly. More importantly, why is this happening somewhere outside the ability for the common Asgardian to either review or participate? You shouldn't need to post notes, you need to have everything said and done evidenced. This isn't personal conversation, transparency matters. You can't honestly expect everyone to start using something shady just because you're too simple to see why it's a bad idea to be using it in order to get to this data.
Slack isn't that great. It can do the job, but at what cost... There's a reason that's not open source.