Just thinking out loud here...
While I still maintain that a 2 wire device has very limited utility for measuring individual cell IR due to balance lead and connector contact resistance, it can be significantly more useful when measuring total pack internal resistance. The reasons why this is the case is very clearly explained by Wayne in post #1
of this thread (and precisely how his wonderfully elegant device works when in 'pack' mode).
Whether this device is capable of handling higher voltage on the input port when in 'internal resistance' mode is unknown and my quick skim of the manual did not provide any clarity. Were it me, I would fabricate a very short lead with heavy gauge wire that connects from the input port directly to the main pack connector (short charge lead) and give it a whirl. If doing so does not smoke the device and precipitates a reasonable and consistent reading, I would agree that this device is more useful for IR measurements than my initial thoughts.
Wayne's is MUCH better though.