The phrase "although not convinced" is correct and usable in written English.
It can be used to express doubt or skepticism about a particular idea or argument while acknowledging it.
Example: "I appreciate your perspective on the issue, although not convinced, I will consider your points."
Alternatives: "even if I'm skeptical" or "despite my doubts."
Maybe it's just jealousy, although Rifer's not convinced.
The consolidation of air service at hub cities is real, although I'm not convinced that it is as serious of a problem for the Cincinnatis and Pittsburghs of the world as the authors make it out to be.
I also can't see gold-plated pensions continuing far into the future, although I am not convinced there is the political will to address the disparity between public and private-sector pensions any time soon.
Many climbers, explorers and scientists seriously believed in the possibility of a missing link, or unknown creature (although they were not convinced by the more supernatural explanations for the Yeti).
Eventually, by force of repetition, I persuaded him to write it down, very neatly at the corner of his notebook, although I'm not convinced that he ever wrote it up again.
Although Paul Goggins was not convinced by the detail of the Marriage (Same-Sex Couples) Act 2013, he supported civil partnerships legislation and voted consistently for progressive LGBT rights legislation.
I think we have found some common ground, and although I'm not convinced about things falling from the sky I am convinced that we will get clarity on this as a party as long as we are willing to discuss it.
Audiences select a menu of shows that go under titles such as "Challenging" or "Dreamy", and although I'm not convinced that one main course and a couple of side dishes would create a sufficiently substantial evening for an over-eager theatrical truffle-hunter like me, extras are available.
He made no attempt, either, to deny the damage inflicted on the international standing of England and the Super League over the last month, although he is not convinced that the game in the northern hemisphere is as far behind the NRL as the World Cup has suggested.
Her daughter offered a few reasons, and although she was not convinced, Grandma Liu stopped arguing.
