How do mechanisms of acidic cleavage of ethers differ for anhydrous, concentrated, and aqueous HI?

I have seen the usage of anhydrous, concentrated, and aqueous HI for the acidic cleavage of ethers. What is the difference in the mechanisms and which will follow either of SN1/SN2 mechanism?


Once the the oxygen is protonated, which cases would favor a carbocation formation (hence putting the iodide at a bulky site), and when the reaction follows SN2 mechanism as the leaving group is good (hence putting the iodide at a less bulky site)?


