I'm gonna sound like a dick and I know this, but part of the problem you're experiencing is that 2 minutes / 100lcm is really more of a medium lane pace. In the medium lane you'll be the one in control of the lane and doing the overtaking and you'll have fewer of the problems that come with being overtaken. No one will be annoyed with you in the medium lane. They may be less competent swimmers that you're having to pass but its a bit like driving above or below the speed limit on a crowded highway one causes fewer roadblocks than the other.

Relatively empty pool or down under 1 minute 40/45 or so go for the fast lane. Crowded pool or above 1 minute 50 per 100m, medium lane...

My 2 cents anyway.