The linked post essentially performed a benchmark of lemmy apps and if they properly display the formating options available. Sync got 3rd last place, position 18 out of 20 apps, with a score of 6.9 out of 10. There's a comment that essentially contains the test set. I hope we get some fixes, cause some of the problems have been around for a while.

In my personal experience the issues with spoiler tags, and some of the embedded images and their sizes is rather annoying. For example this comment shows perfectly fine on desktop, but becomes a garbled mess on sync (as you can tell by my comment, blaming the bot). Also note that while sync technically gets 3/3 for the images, the last image should be text-sized between the "arrows". It isn't, it's just huge (and consequently a pixelated mess).

Edit: fixed link to example comment for spoiler.