I run with a little under 1" from frame to bump stop with 1.12" bars and I still occasionally contact the bump stop. Granted I do not use a progressive bump stop like the factory ones, but if you hack the top off a factory bump stop it's not a progressive bump stop anymore and can't be treated like one.
Running /6 bars and no bump stop at all wouldn't work at factory ride height, it'll go metal to metal and destroy the suspension parts.