Typically the tabs need to be removed with billet uppers because they are too wide for the handguard.
However, it is possible to save most of the tabs with some uppers. You still have to grind off part of the tab, however, if you remove some of the inside (instead of just taking them off all together) it will work. Basically you just need to slowly remove the inside of the tabs until they fit. Depending on your upper, this allows you to keep the tabs and allow the handguard to fit.
Due to the way we designed the handguard and the built in redundancies, you won't lose functionality if your pursue this modification. We've had a number of customer modify their handguards in this way without any issues.