The phrase "although it may be true" is correct and usable in written English.
It can be used to introduce a contrasting idea or to acknowledge a point while suggesting that there is another perspective to consider.
Example: "Although it may be true that the project is behind schedule, we have made significant progress in other areas."
Alternatives: "even if it is true" or "while it might be accurate".
Although it may be true that, as Professor Shaw notes, "[t]he ambitions of this book..
For although it may be true that everyone loves a winner, changes to the Triple Crown would leave everyone wondering what had been won.
For although it may be true that the upwardly mobile working classes do not want fundamentally to change society, their very ascension does change it.
Although it may be true that these treatments and tests would decrease costs for the population over the long term, they are not likely to pay off for an H.M.O.
Although it may be true that a censure by itself has no constitutional basis (front page, Nov. 10), the scholars who testified before the House Judiciary Committee missed the point.
Although it may be true that I (1) bid on eBay and (2) bought Fire King dinner plates, I would like to point out that I did not (3) stand in line at the post office to get a money order.
Although I do not agree, it may be true now that no legislation is going to make much difference in gun violence, although the arguments of possible insurrection, etc. are ludicrous.
Although it may be fundamentally true, at the level of atoms and basic molecules, that you are what you eat, we shouldn't expect particular compounds to enter our bodies, unchanged in form and function.
It is not a true migrant, although it may be locally nomadic due to the changes in vegetation, and may leave its territory after the breeding season.
Although that may be true, it might not be the teachers that they were listening to.
Although this may be true, it presupposes that we already have a grasp on the sense in which properties belong to objects and how this differs from the various ways that objects belong to or can be attributed to things, and that we can call upon this informal understanding in interpreting the theoretical account.
