I think you would lose the ctis feature as the stock rims are not set up for it. I have not heard of any being converted as most folks think the system is troublesome and prone to leaks which leads to removal. Most trucks on gl that have it usually have at least one tire flat in the pics. Lines would need to be disconnected and possibly removed if you are going to the 11r20 duals.
If you go this route, also need to pull the speedo adapter to get the right read out as the a1 & a2 with the super singles have it and the base model does not.