Re: anti-canting equipment
If you want one like on a T2k (I wouldn't), then you should arrange to have the muzzle turned for this device before it's lapped.
If you simply clamp one onto an existing barrel, your tune will change but the barrel should shoot as well.
You never know.
You don't have to watch your cant really. I put the crosshair on the target as it naturally levels, and glance at my scope mounted level to confirm all is in order. If an illusion exists, I take that into account in my shooting.
For one shooting situation, without change, there is no need to look at it further.