I don't dive a twin tank setup, only single tank, but my experience disagrees with the notion you are putting forth about 22" being more than adequate with a single tank setup. I recently swapped my 22" hose out for a 26" because there was strain when I turned my head to the left with the octo in my mouth. I had borrowed a 24" hose from a friend and that alleviated the problem, but the local dive shop did not carry 24" hoses, so I purchased a 26" and it works great. It is not excessively long, especially considering that the hose length is measured from end to end so roughly 3/4 of an inch is consumed by the sections threaded into each regulator stage.
Obviously this is a case of "mileage may vary" and may be dependent on factors such as how high the tank/tank valve sits relative to the persons shoulders/head as well as the configuration the LP ports on the 1st stage being used. All I know is that with my setup (MR22 1st stage) I found the 22" hose too short and now have a 22" hose collecting dust in a bin.
To the OP, it may be prudent to take your BC and regulator to a shop and put it on with different hose lengths to see what will work best for you.
-Z