I looked into doing this a few years ago. FWIW I think my bike was built around 2013. I used the synapse for a ton of road riding and loved it, so I wanted to try to keep it around even though I wasn't doing endurance rides on the road much anymore.
The clearances weren't great with the stock fork, so I wasn't confident about it and decided it would be better to go with a different frame given that swapping wheels and fork, plus probably upgrading the disc brakes, was going to be costly.
How much space do you have with the 28s?