You don’t need to change your gas tube. Adjustable gas blocks are needed for running suppressors. If you don’t plan on doing this then no, you don’t need one. One thing we would request you do while it’s apart is measure gas port diameter. Also give full measurements on recoil system. Read up on threads here to find out why.
It’s your rifle so you use it how you deem fit, but.... 308AR rifles are not home defense rifles unless you own a ranch in Montana. You will over penetrate anything you shoot at and it will go through your target, your house, the neighbors house and the house next to it if it doesn’t hit a solid steel object. Just saying, in case you didn’t think of that.