Xringer-
Getting the 1/4" lines back out of the tank was a bit challenging. If your unit is working fine, I'm not sure I'd convert it to an external loop unless I had a problem. (aka...If it ain't broke, don't fix it)
The external loop does work great for me, and my old dumb HWH is now high tech digital. LOL
Just an FYI, the 1/4" lines on the A7 are double walled...don't ask how I know