I guess you can start by considering a pack the "no wake" zone.
When moving back up to start a drift, go outside the pack or separate from other boats by about 150 ft. This is 3 casting distances and nobody should complain about that.
When drifting, I don't get nervous until someone is within 2 cast lengths or about 100 feet. If you are passing a trolling boat try to go below them, where they already trolled over. Separate at least 150ft from their boards. Central and Eastern Basin maybe more.

Common sense is not always common. I had a perch fishing boat setup anchor only 60 yards below me then complain when I drifted within 20 feet of his boat. We were the only 2 boats out there. I told him what to do with his anchor and then we caught two walleye within casting distance from him. Maybe I wasn't the best example but he drew first blood. Knuckleheads are out there everywhere.
Rickerd