Keyword: decently. (...in the dry, with large amounts of hand strength.)

You have this backwards- travel agents are to compensate for shorter pull levers not pulling enough cable to allow a linear brake to open wide enough its pads don't rub on the rim (and change the leverage ratio...)

That lever is a quick release, it won't do a thing but make the brakes looser- the brakes might be working "better" with that flipped open because you're applying pressure with a stronger part of your hand as you squeeze the brake lever to stop.